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Tech and Marketplace => I need help with my game! - Technical Discussion => Topic started by: P-feif on May 15, 2014, 05:31:10 pm



Title: Mrs. Pacman help
Post by: P-feif on May 15, 2014, 05:31:10 pm
Today I found time to strip down my Mrs. Pacman. I bought it with a few problems and I'm determinded to get it working. So here are some things that I noticed and I'm wondering if you guys can help explain some of it. Keep in mind this is a Wells Gardner monitor (pic somewhere below).

This is the PCB. Notice anything missing? Isn't there suppose to be a gray ribbon cable with a daughter board mounted next to the PCB? This one does not have it and yet it still plays Mrs. Pacman. It clearly says Midway Pacman on the board and I know that Mrs Pacman is just a Pacman that's sort of modified. I'm wondering if maybe the original PCB died and someone fixed this game by installing a regular Pacman board with some Mrs. Pacman chips installed. I can see where there are chips that have hand written tags on them (Note: This game has a speed up mod so I don't know if the chips were installed for the speed up mod or to make this board play as a Mrs Pacman, or both)

(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/10267778_10202032401748641_7547249091106049368_n.jpg)

(https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/10330405_10202032403308680_7866836442489498223_n.jpg)

(https://scontent-a-ord.xx.fbcdn.net/hphotos-prn2/t1.0-9/10372022_10202032404028698_8236745301095163837_n.jpg)

Also this game has a piece of dark colored plexi-glass over the monitor screen, as it should, and with it in place I did not notice all the burn in that this tube has. Now that I've taken it out of the game it's easy to see just how bad the burn in is. It's bad so I don't know if I want to live with it or not but for now let's just assume that I'm going to live with it (if you have a good tube let me know). What I noticed is that the burn in is there twice. It looks as if thing has been through hell and back. I can see two differant types of fonts and two mazes, as if the image has been moved or shifted and then the game was used like that for a long time (again). This is another clue that this game has been broght back to life with this "other board" that I found in it (don't ask me how I didn't notice it when I looked it to buy it but it's what I have to deal with now).

(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/r90/10322772_10202032394588462_2321418606285932465_n.jpg)


Anyhow here's some more pictures just for fun and as long as I figured out how to post pictuers to the forum.

(https://scontent-b-ord.xx.fbcdn.net/hphotos-frc3/t1.0-9/10256334_10202032393268429_5623606779151187197_n.jpg)

(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-prn1/t1.0-9/10277583_10202032399148576_4764859089837299691_n.jpg)

(https://scontent-b-ord.xx.fbcdn.net/hphotos-prn2/t1.0-9/10262217_10202032406148751_8109605459985673547_n.jpg)

Notice that ground strap that's cut off? I can't find where it's suppose to go and I'm not even sure that it belongs there. Any Ideas???
(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-prn1/t1.0-9/10330457_10202032405388732_6161850233797116351_n.jpg)

(https://scontent-a-ord.xx.fbcdn.net/hphotos-prn2/t1.0-9/1797630_10202032394868469_7477943845387647572_n.jpg)

Cut off ground wire? I am guessing that I should hook this back up? One end goes to the neck board. The other end goes to what I think is part of the degaus wires around the picture tube. At the neck board there is a second ground wire that also goes the the chasis as a ground.
(https://scontent-b-ord.xx.fbcdn.net/hphotos-frc3/t1.0-9/10363929_10202032391708390_4453625268709915937_n.jpg)



Title: Re: Mrs. Pacman help
Post by: P-feif on May 15, 2014, 05:33:58 pm
Hold on I just noticed a problem with some of my picture links. The computers being fussy about fixing it and I have to do it one pic at a time. Give me a few minutes.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 15, 2014, 05:42:19 pm
O.k. picture links are fixed. Let me know if you can see them too.


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on May 15, 2014, 06:45:47 pm
it looks like someone did the daughter card elimination mod to the PCB, operators often performed the mod on MS Pacman because the reliability of the
game was poor due to the ribbon cable that ran from the PCB to the daughter card.
I have a PCB with this mod, and it is more trouble free than the one with the stock daughter card.

All MS Pacman PCB's are actually Pacman PCB's with different character roms and the daugther card.
I don't see anything to indicate your PCB has been swapped out, just modified.
(although it is certainly possible, IIRC there is a way of checking by matching PCB serial numbers to the cabinet)
here is some info on the mod http://www.pinrepair.com/video/pacman.htm (http://www.pinrepair.com/video/pacman.htm) I think it's mod #3

My explanation for your double burned monitor is a simple one, it appears like it was setup with the factory settings long enough to get burned in
and then sometime later, an operator readjusted the monitor to compensate for aging components in the monitor chassis
and then got the second burn, monitor image placement is all about settings on the monitor and not usually the PCB itself.

I see two cut wires on your monitor chassis, a tan wire near the power cord which in most cases would attach to any field ground (like the ground wire on the main AC power cable, or on the AC line filter ground)

and the black wire from the neck board, which should connect to the aquadag groundstrap wire, this wire is often cut to remove the chassis for repair, and can be reconnected with a wire nut or crimp quick disconnect terminals.

You lucked out getting a Wells Gardner 4900 in this cab, it is a good monitor and after a recap and reflow should provide a great picture and service for years to come.
Tube swaps are also possible if you can find a 19" TV with a compatible tube.

I always recommend that when someone gets a ms pacman that they check all the fuses and the fuse holders on the bottom of the game as they are often in need of replacement.
 
I hope I'm not getting too technical :-) Let me know if I am.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 15, 2014, 08:18:41 pm
No you're not getting to technical. I have a mild electrical and electronic backround mostly in the automotive field. This is totally differant but I am able to understand it and I'm trying to learn what I don't understand.

That's good that you think it's just a PCB mod to eliminate the daughter board because after looking at it, it made me start to wonder if such a thing existed. Now it makes sence. Everything I've seen about them says that they are just a pacman board. At first when I noticed that the daughter card wasn't there I thought "BOOTLEG BOARD", but then I saw the Midway Pacman logo and I knew that something had been done that I was not aware of. When I get some time I'm going to follow your link and read up on that.

Monitor wise I just noticed that the font looked differant in on set of burn in vs. the other set of burn in. I guess it could look like that if the picture was shrunk down so it is what it is. I've heard of using a TV tube but I have not been able to find one that fits the bill for this one. Even John had a list of compatible TV tubes that I read over. Either I missread it or it just didn't list one that would work. So if you know of a model that will swap please tell me. I'll start combing tv shops to see what they have lying around.

I have a kit from Bob Roberts with caps and the color transisors and resistors and a few other parts. If it still has no read tones then I guess that means that the tube is bad or I have no signal from the PCB. I guess we'll see what happens. I sort of bought this thing so I would have a good candidate to get practice on so I just decided to go ahead with the monitor rebuild. Wish me luck.

That tan wire that you spoke of is acutally a bare uninsulated strap. I'll have to try to figure out where you think it should be attached. The black wire I kind of figured it was cliped so thanks for you conformation. It will get and insulated spade connector.

Thanks tht ought to get me going for now. Believe me I'll be back with more questions.


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on May 15, 2014, 09:55:46 pm
I wanted to provide a few links I felt may be of use to you, they really helped me in my early days and some are related to Ms Pac

First, you may want to check out Bob Roberts' page on AC wiring, it has a photo of the AC line filter I was talking about and, while written for someone using a switching power supply, is still useful to help you troubleshoot some of the wiring in the AC section of the game , it's here http://arcadecontrols.com/BBBB/acwiring.html (http://arcadecontrols.com/BBBB/acwiring.html) In the case of your monitor, I would recommend replacing the cutoff bare ground strap with a new ground wire, I use green wire for AC circuits you can get at home depot cheap, I got a whole roll for like $5.
and I swear it looked tan  ;D but then the monitor on my laptop isn't the best.

Also be sure to check the fuses on your monitor chassis, those can and do fail as well on 4900s I think they are soldered in and often covered with plastic clear (now yellowing) tubing, if the HOT and or flyback has gone bad they can take out the fuses.

Here is a page on pacman, I often recommend this page for people, it has general information on fixing pac boards and other things relating to these cabs http://lawnmowerman.rotheblog.com/ (http://lawnmowerman.rotheblog.com/)

I have heard that Sanyo 19" DS19390 model TV's have a compatible tube in them. I wish I could be of more help with the tube swapping, but I have yet to perform one, like you said you can just visit tv shops or thrift stores and maybe you will get lucky. Once you get your monitor going you will be able to decide whether you are unhappy with the image enough to swap it out.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 15, 2014, 10:39:27 pm
Actually the entire game was working. The monitor just had no red tones. So I'm just doing a full rebuild to fix it and make sure that I minimize future problems, or at least what bob roberts says is a rebuild.

Thanks for the info. I had found the lawnmowerman site, it's great, but I hadn't seen the A/C wireing one from bob roberts so I'll make sure to look that one over. If I happen to find one of those tv's I'll let you know if the tube fits or not.

Yeah, I found the soldered in fues. I just shook my head. Why would you solder in a fues?


Title: Re: Mrs. Pacman help
Post by: P-feif on May 17, 2014, 09:51:42 am
This is for anyone working on a WG4900 monitor like I am attempting. I wasn't sure where some of the parts went that Bob Roberts sent me so I sent him a note and he was kind enough to reply with the answer that I needed. Along with his answer was this link on how to install a filter cap in the corner of the board, so I thought I would share that link for anyone that needs it. When I looked at my board I just couldn't see this small cap replacing the monster cap I was looking at. I should have gone with my instincts but at the same time I'm also glad I played it safe.

http://www.therealbobroberts.net/wg49.html

I'm going to look in the factory Mrs. Pacman manual for a monitor schematic but if it's not there does anyone have a link to one on-line?


Title: Re: Mrs. Pacman help
Post by: John's Arcade on May 17, 2014, 02:43:18 pm
I haven't read everything but I did notice the filter board between the PCB and the harness. Remove that. It's not needed and causes all sorts of problems.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 17, 2014, 02:55:41 pm
I think it's already gone. What do you know about the yellow ground strap that runs from the coin door area to the PCB area? In mine it's disconnected and I think I remember reading somewhere that it was to stop some sort of RF interference. That sound right? Hook it back up or leave it off? And what does it hook to because I haven't found a spot that looks like it should go to?

With a little luck it'll start raining soon and I won't be able to work on outdoor projects which mean I can work on Mrs Pacman in the basement.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 17, 2014, 05:13:59 pm
Ha! Bob Roberts just sent me an e-mail saying the 330uf 200v cap he sent was the wrong one and he's sending me a 470uf 200v cap to replace it. I guess it's a good thing I sent him that e-mail asking for board locations for some of the other parts he sent.

Between Bob Roberts, the John's Arcade video's and forum I'm getting things figured out. Thanks to all that have helped. I'll keep asking questions and when I get it working I'll have to post some pics or maybe a short video too.


Title: Re: Mrs. Pacman help
Post by: John's Arcade on May 17, 2014, 06:03:48 pm
I think it's already gone. What do you know about the yellow ground strap that runs from the coin door area to the PCB area? In mine it's disconnected and I think I remember reading somewhere that it was to stop some sort of RF interference. That sound right? Hook it back up or leave it off? And what does it hook to because I haven't found a spot that looks like it should go to?

With a little luck it'll start raining soon and I won't be able to work on outdoor projects which mean I can work on Mrs Pacman in the basement.

Oh. sorry. You are right the filter board is gone.

The ground strap goes somewhere. I would just ground it to the closest screw.


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on May 17, 2014, 11:36:15 pm
Here is a link to the monitor manual for the 4900 series monitors, it includes schematics http://www.vernimark.com/arcade/archive/monitor/mon_rc__wg-19k-4901-06-51-56.pdf (http://www.vernimark.com/arcade/archive/monitor/mon_rc__wg-19k-4901-06-51-56.pdf)

The yellow cable used to hook up to the now removed filter board, since it's gone just do as John recommended and run it to a ground screw.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 18, 2014, 10:36:46 pm
O.k. I've seen pictures of the filter board. If I can find a ground for it I'll use it otherwise I'll just tuck it off to the side and leave it unused.

Thanks for the link! I printed that!


Title: Re: Mrs. Pacman help
Post by: P-feif on June 02, 2014, 09:53:24 pm
O.k. finally found some time to work on this monitor. I've got about 75% of the caps replaced and still need to do the color transistors and a few resistors and the rest of the caps. When it's done I don't want to reinstall the monitor untill I can replace the missing leg levelers. It's much easier to tip the cabinet now with no monitor in it. So my question is, where can I get leg levelers for this Mrs. Pacman and while I'm at it I'll get some for my Space Invaders too?


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on June 02, 2014, 10:37:34 pm
well you can get leg levelers from pretty much any arcade parts dealer, but for standard ones I get them here:

http://www.twistedquarter.com/index.php?main_page=index&cPath=219_220 (http://www.twistedquarter.com/index.php?main_page=index&cPath=219_220)

 I have also looked into leg levelers with teflon from quarter arcade, but those are more expensive (and come only in a bag of 24 IIRC)



Title: Re: Mrs. Pacman help
Post by: P-feif on June 04, 2014, 09:09:52 pm
Looks like they've got a good selection I'll look into it more. Thanks!


Title: Re: Mrs. Pacman help
Post by: P-feif on June 07, 2014, 11:24:17 pm
Thanks lordkahless214 I orders a set from them.


On to the next thing. I just got done installing the cap kit from Bob Roberts on my WG 4900 monitor. I noticed I had an extra cap and could not find the location on the board. The sheet with the kit said the location was C366. Eventually I did find that location but there is no cap installed there. It was left blank from the factory. There is a diode at that location that the non banded side is soldered to the + hole that he cap would go to, and then the diode skips over the - hole and goes to a third hole on the board. So do I install this cap at C366 or leave it out?

Also I discovered why I was having such a hard time understanding the Wells Gardner schematic for the 19" monitor that is in the Mrs. Pacman manual. The Mrs. Pacman manual has a schematic for a WG 4600 monitor. My Mrs. Pacman came with a WG 4900 installed. After digging around the Mrs. Pacman manual I could find no mention of a WG 4900 so either Midway never put the WG 4900 schematic in the manual or Mrs. Pacman never came with a WG 4900 and someone swapped in a WG 4900 at some point. Well it's what I've got to work with so I'm sticking with it especially since I have the entire cap kit installed now and just a few resistors and color transistors yet to install. Opinions?????

Also one of the caps that I replaced, I had a real bad time getting the old one out. For some reason the legs were stuck and would not come out of the board. At some point the cap just fell off and the legs were still in the board. When I looked at it I found that someone had cut off a cap and soldered a new one to the legs that were still there. I considered this a very hokey repair. So I kept working at it and eventually got the old legs out. One of the solder pads was half missing. I'm pretty sure there was an issue there and someone just hacked it together. I installed the new cap and soldered it the best that I could to the half pad, and then bent the leg over to the next solder point along that trace and soldered it to that point. Let's see how that works.


Title: Re: Mrs. Pacman help
Post by: iankellogg on June 08, 2014, 03:07:21 pm
i'll have to look at it for C366, i really can't remember the deal with that.

As far as ms pac goes, I dont believe they ever came in a K4900 so I would consider yourself lucky as the K4900 is one of the best monitors you can get.


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on June 08, 2014, 05:45:51 pm
I remember when I did the 4900 in my Q*bert that one cap was with a diode in the same holes like you are describing so I  kept it like that, but I don't remember which cap it was on.

I will be doing more work on that cab on Wednesday, so I can look when I pull it out from the wall if you haven't found an answer by then.


Title: Re: Mrs. Pacman help
Post by: P-feif on June 08, 2014, 09:31:09 pm
I remember when I did the 4900 in my Q*bert that one cap was with a diode in the same holes like you are describing so I  kept it like that, but I don't remember which cap it was on.

I will be doing more work on that cab on Wednesday, so I can look when I pull it out from the wall if you haven't found an answer by then.

The one you're talking about is at C373, and yes I did change that one. Per the Bob Roberts sheet that came with the cap kit... "*This cap is across D306 in some versions with the - side going to the banded side of D306." Yes I changed this one.

As for the cap at C366 the sheet doesn't say what to do with it. It is in the same location as a diode at D307 sharing only the positive leg. The negative leg for the cap is blank on my board with nothing in it. There is currently a diode in that location. The negative leg of the diode stretches across the cap location and goes to another hole in the board all together and does not share the negative hole with the cap.

Thanks for any help you guys can give. So far my searches on the internet for an answer to this have not gotten me anywhere.


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on June 08, 2014, 09:48:17 pm
Ok so it was C373 it's been a long enough time I couldn't remember which one it was.

well I figured there was one thing I could do to help you out here, I called up my arcade op friend who is very familiar with this particular model and asked him about your issue, he said that like most Wells Gardner monitors, there were several revisions to the 4900 chassis and also some hot-fixes to the boards during production, some had cap 366 as an electrolytic, some had it as a non electrolytic cap, and others still omitted it entirely.
he told me you should look for any remains of legs in the holes that would indicate there was a cap there before, if it's not there go ahead and leave it out, don't put it in unless you have issues, because it may be a factory fix for something.
According to him several cap kit sellers omit this cap by default due to the fact that c366 is most often not there at all or not electrolytic.




Title: Re: Mrs. Pacman help
Post by: P-feif on June 08, 2014, 10:18:42 pm
O.k. thanks. From what you are saying I think I should leave it out. There is no evidence of anything ever being installed at that location. Even solder on the pads is obviously from the factory and has not ever been touched.

So I'm going to get to installing the 3 color transistors and the resistors the Mr. Roberts provided (already did the BIG filter cap and mod). As a matter of fact I'm looking up resistor color charts to help me I.D. the old resistors as I pull them out. Mr. Roberts had sent me a separate e-mail explaining most of their locations but I'm double checking everything as I go. Just to be perfectly clear, resistors do NOT have polarity correct???


Title: Re: Mrs. Pacman help
Post by: lordkahless214 on June 09, 2014, 12:44:05 am
resistors should not be polarized, just diodes and most capacitors, and there is no harm double or even triple checking your work, one mistake can mess up your project or send you looking for a problem caused by something you thought you fixed (we have all done that once)

you should have a beautiful picture on that monitor once you finish it and get it adjusted, the 4900 is one of the top 3 monitors ever made in my opinion.

 one thing to make sure you do on this chassis is reflow the solder on the RGB input headers and also the large rectangular resistors, since they can develop cracks over time it's good to do it now since you have the chassis out already


Title: Re: Mrs. Pacman help
Post by: P-feif on June 09, 2014, 10:22:59 pm
resistors should not be polarized, just diodes and most capacitors, and there is no harm double or even triple checking your work, one mistake can mess up your project or send you looking for a problem caused by something you thought you fixed (we have all done that once)

you should have a beautiful picture on that monitor once you finish it and get it adjusted, the 4900 is one of the top 3 monitors ever made in my opinion.

 one thing to make sure you do on this chassis is reflow the solder on the RGB input headers and also the large rectangular resistors, since they can develop cracks over time it's good to do it now since you have the chassis out already

Sounds like good advice. I'll make sure to do that.


Title: Re: Mrs. Pacman help
Post by: P-feif on July 15, 2014, 04:18:44 pm
O.k. been awhile since I had time to work on this thing. I got ALL of the parts that Bob Roberts sent me installed. All caps, all color transistors, all resistors, and the chasis transistor. I even crimped on a new power connector to the monitor board power wires, and then broke my (really cheap) crimp tool so I bought a new one this morning (still need to crimp the other side of the connector to the harnes in the cabnet). I'm almost ready to put this monitor back in but I'll like to do just a little bit of repair to the cabinet first, just easier to move and lay on it's side without the extra weight of the monitor. However there is one more thing that I'd like to do for this monitor before I put it back in the game. There is a thermistor at TH 501 on the board. The coating has pealed off of it and so since it's all appart I think that now would be a good time to replace it, need it or not. According to an e-mail that I got back from Bob Roberts he does not carry these and he even says that he thinks it will work just fine as is, but like I said it's appart now would be a good time to put a new one in. I visited a local electronics store and they didn't have it so I've got to do some searching. Anyone have any idea where I can get one? A new one not one pulled from a donor monitor.

Stats:

Board ref no. - TH 501
Name - Thermistor
Part number (according to the WG 4900 manual) - 201X0100-112



That's all I've got on it.

And just for John, they had two Wizard Of Oz pin ball machines in the back of the store. I think they wren't even pluged in.  http://www.abelelectronics.com/


Title: Re: Mrs. Pacman help
Post by: P-feif on July 17, 2014, 03:32:47 pm
O.k. I found 3 free G07 monitors with possibly good tubes. My Mrs. Pacman manual says that the Electrohome tubes can be put into a WG4600 monitor. My game has an WG4900 in it. Anyone know if the G07 tubes with work in a WG 4900. The shop that has them put them outside for anyone to pick up free for nothing. I stopped to look at them but no one knew if the tubes would work in my WG 4900 so I didn't take any of them. Thoughts? Take them or leave them. Keep in mind I don't want to store them just to store them. Got enough stuff lying about as it is.


Title: Re: Mrs. Pacman help
Post by: P-feif on July 28, 2014, 03:16:41 pm
I've been calling around today looking for a suitable replacement and I found this. Any chance that anyone knows the specs on this thermistor? I'm waiting for a call back from one of their engineers. If I can figure out which one will work then I'll pass along the info for everyone to use.  


http://www.ussensor.com/inrush-current-limiting-power-thermistors


Title: Re: Mrs. Pacman help
Post by: jtslade on July 30, 2014, 11:05:27 am
Your tube is an RCA tube, sticker in pics.. All of my G07's have RCA tubes. It's what I used on my G07 tube swap.

Also remember to use continuity setting on your multimeter to test from the soldered leg of each cap and follow the trace to ensure continuity, especially the one you mentioned that had a lifted pad on the pcb


Title: Re: Mrs. Pacman help
Post by: P-feif on July 30, 2014, 09:24:39 pm
Thanks maybe I'll go back and look at those free-bee's.


Title: Re: Mrs. Pacman help
Post by: John's Arcade on July 31, 2014, 08:22:33 am
Tube manufacture has nothing to do with anything when doing a tube swap.

It's about the tube angle in relation to the neck (if doing a YOKE swap), socket size, and Yoke impedance.

Here's a list of suitable TV tubes for popular chassis:

http://junknet.net/donor-tvs

Measure the YOKE to see if it's compatible.


Title: Re: Mrs. Pacman help
Post by: P-feif on July 31, 2014, 05:41:48 pm
Thanks John. I looked all through that list and I don't see anything about what tubes will fit the WG K4900 monitor. I may just try to rejuvinate this tube. I don't have the equiptment to do it but the shop that was giving away the free monitors (I drove by today and didn't see them sitting out there so I'm guessing they are gone now), said that they could rejuvinate it for me. So I may just pay them to do it. I have everything done on the monitor board except that thermistor at th501.

Every company I've called about buying a thermistor says that they can't cross referance the Wells Gardner part number and so I don't know what other part number to give them. I can't give them the specs on the thermistor because the WG manual doesn't list the specs. I did find an article on KLOV that talked about a few differant parts that could work and who to buy them from but when I called the company they had since disscontinued those parts and no longer make or sell them. If we can just figure out the specs on this thing I'm confident that we can find a suitable replacement for it. Everyplace I search on the net I find people that want replacements for it too. GRRRRRR!

How does John say it? ARRGGGGGG!  ;)


Title: Re: Mrs. Pacman help
Post by: P-feif on August 01, 2014, 04:31:39 pm
o.k. just got off the phone with a place called Mouser Electronics. They have lots of thermistors. What they need to know are the specs (same as I've been hearing) but this guy talked to me about what specs which is more then any other place has done so far. So let's work together here and see if we can figure this thing out. They need the risitance at room temp, is it an NTC or PTC (resistance increases or decreases as temp goes up), the temp range (upper temp limit) and maybe the volts and amps that it operates at?

If you have any of this information post it here.


Title: Re: Mrs. Pacman help
Post by: P-feif on August 01, 2014, 07:45:51 pm
I found some more. I was lookint at the schematic and I noticed some numbers associated with the thermistor at th501. So I called back the tech at Mouser and talked with him some more. These are the numbers that I had noticed PH631-138F and PTC-070. From that we were able to fiqure out that it is a PTC thermistor and NOT and NTC. We speculated that it might be a 70 deg to 138 deg F range part and so he looked up some more based on this information and found this. http://www.mouser.com/Search/Refine.aspx?Keyword=b59750b0120a070  These are two possible candidates. What we need to know at this point is what is the resistance at room temp. Hopefully in the next few days I can de-solder one leg on this thing and measure the room temp resistance. That just might give us a good enough spec to get a really close part that will work as a suitable replacement. Anyone happen to know the resistance at room temp on one of these???

Closer... We're getting closer.  :o


Title: Re: Mrs. Pacman help
Post by: alby13 on August 02, 2014, 02:40:08 am
continue updating.


Title: Re: Mrs. Pacman help
Post by: P-feif on September 08, 2014, 05:02:41 pm
O.k. finally got a little time to unsolder one leg of this thermistor and get a room temp resistance value. 7.2 ohms is what I got (assuming it's still a good part). Just got off the phone with Dan at Mouser, we came up with a list of about 7 or 8 posible thermistors but it's still somewhat of a guess. I'm thinking of sending a note to Bob Roberts to see if he has any input on this. Hey if anyone knows what will work wouldn't it be Bob?

Here's a link to the "possible" thermistors for this monitor degause circuite.

http://www.mouser.com/Circuit-Protection/Thermistors/Thermistors-PTC/_/N-axfwr?P=1z0x71qZ1z0s0adZ1z0z7l5

Any input you guys have would be greatly appreciated.

Useing ohms law, 7.2 ohms and 120 volts would be roughly 16 amps (16.667 amps). So that's at room temp anyhow. It's headway but still frusturating to fiqure out.

And if anyone would like to see the schematic here's a link (provided by another John's Arcade Forum member) http://www.vernimark.com/arcade/archive/monitor/mon_rc__wg-19k-4901-06-51-56.pdf



Title: Re: Mrs. Pacman help
Post by: P-feif on September 09, 2014, 12:57:16 am
So I just got home from work a short bit ago and just for fun I checked the resistance on this thing one more time. This time I got 6.6 ohms. I walked away and did it again.... 6.6 ohms. So did I goof up the measurement the first time? I think I may have been just barely letting the leg come in contact with the solder pad the first time. So now that I have a reading of 6.6 ohms I went back to Mousers web page and found that this is the only one with a 6.6 ohm rating. So did I find it? I need to somehow confirm it.

http://www.mouser.com/ProductDetail/Vishay/PTCCL17H401HBE/?qs=vB0g00R0fR%2fBNM6bWcpDMw%3d%3d

I guess the big question is the amp rating because it's not what I calculated but that doesn't mean that I was right to begin with.


Title: Re: Mrs. Pacman help
Post by: VertexGuy on September 10, 2014, 07:52:14 pm
Thanks John. I looked all through that list and I don't see anything about what tubes will fit the WG K4900 monitor. I may just try to rejuvinate this tube. I don't have the equiptment to do it but the shop that was giving away the free monitors (I drove by today and didn't see them sitting out there so I'm guessing they are gone now), said that they could rejuvinate it for me. So I may just pay them to do it. I have everything done on the monitor board except that thermistor at th501.

Every company I've called about buying a thermistor says that they can't cross referance the Wells Gardner part number and so I don't know what other part number to give them. I can't give them the specs on the thermistor because the WG manual doesn't list the specs. I did find an article on KLOV that talked about a few differant parts that could work and who to buy them from but when I called the company they had since disscontinued those parts and no longer make or sell them. If we can just figure out the specs on this thing I'm confident that we can find a suitable replacement for it. Everyplace I search on the net I find people that want replacements for it too. GRRRRRR!

How does John say it? ARRGGGGGG!  ;)

1995 RCA tv


Title: Re: Mrs. Pacman help
Post by: P-feif on September 11, 2014, 04:10:09 pm
Really? Interesting! Thanks, I just might look for one!


And for the record I got word back from Mr. Roberts today. He has no idea if that thermistor that I found at Mouser will work. Crap.....


Title: Re: Mrs. Pacman help
Post by: P-feif on September 20, 2014, 11:31:17 am
Never did find a thermistor to replace that one so I decided to put it back together and see what I've got. All I can say is the game worked and played before I took the monitor out. Now all I get is this.

(https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xpf1/v/t1.0-9/10666100_10202788338126578_8353261557120203657_n.jpg?oh=6dd5701b5adf835d50b6a7cf23847ee1&oe=54CE29F0&__gda__=1418675087_31d72fb9951604996767d11dcf5965d0)

Maybe when I vacuumed it out I caused an issue with the PCB or one of the fuse blocks??? Not sure where to go with this but I'm determined to figure it out. Well anyone seen this before???

Also I noticed that it does not go through the boot up sequence. No blocks of colors on the screen or the white test pattern, nothing. I tried the test switch and it did nothing.


Title: Re: Mrs. Pacman help
Post by: P-feif on September 21, 2014, 04:46:34 pm
Yay!!!! I have THE COLOR RED now! Notice how the red is shifted WAAAAAY low on the screen??? I think it just a convergence adjustment. Like everything else I've done on this thing, never done it before, but I'll figure it out. Even with the convergence way out of wack I still played my first game on this thing since last February... until the game reset. Need to figure out why it's reseting. Most likely a loose wire on the main PCB connector or on the self test switch. But hey this is real progress. It's the best it's been since I bought it.

From the last post with only blue on the monitor, it just took some adjustment to get more colors to show up. Still needs a bunch but I'm getting there.

(https://scontent-a-lga.xx.fbcdn.net/hphotos-xaf1/v/t1.0-9/10003973_10202795275540009_7093230734527909008_n.jpg?oh=0d2473f51deb842ae7817244d08bf946&oe=54CC460E)


John you got any good tips, especially for getting the convergence right???? Is it possible that the drive on the fly back is turned up too high???

You know I was thinking about this and looking at the above picture I noticed that most of the red that is not converged is just skewed to the bottom of the screen, but I noticed something strange. If you look closely there are a few spots in the picture where the red is not skewed to the lower part of the screen but instead, it mirrors the maze. I'm thinking that a convergence issue will not mirror the maze so I'm wonder what is going on here and what to do next. I'm going to research this but "as always" I will be more then happy to take your advice.


Title: Re: Mrs. Pacman help
Post by: mrdude on September 22, 2014, 08:46:27 pm
Does this now come the trial and error part of adjusting those convergence rings?? Glad you have the red!


Title: Re: Mrs. Pacman help
Post by: P-feif on September 22, 2014, 09:53:20 pm
Well after talking with a guy I work with that used to work on monitors for a living he thinks that I might just have the flyback set too high. I agree, it looks way too bright. It might just get a whole lot better if I turn it down a bit. Still need to get the colors set right too. ...................... As soon as I get a little more time to mess with it.


Title: Re: Mrs. Pacman help
Post by: P-feif on September 26, 2014, 04:04:05 pm
Last night I did some adjustment on this thing. Got some really great color out of it, except I can't get enough red to show up. If I really crank up the red cutoff then I can see the red features on the screen but I also get all kinds of other things showing in red that shouldn't be there, red bars down both sides of the screen, red shadows of every object on the screen. If I turn the red down enough that you don't see that stuff then you loose things like the red dots that the 6th game board has. Also in the attrack screen some of the red lettering gets hard to see. Also after it's be on for 5 or 10 minutes I starting getting a hum bar accross the screen too. So it's got some issues to work out. I'm betting the hum bar is some sort of power supply issue (power supply or transformer). I "THINK" the red issue might be a weak red gun but I don't have enough expieriance to really know for sure. If I crank up the green or blue cut off I can get the entire screen to turn green or blue, but I can only get red bars on the sides of the screen if I crank up the red. I'm going to try to check the voltages (need to look up how on this thing) and get any power issues straightened out so I know that a power issue is not influancing this thing, but my best guess is a week red gun. So if that's the case I need to find a way to rejuvinate the tube because I don't have the equiptment to do it.

Thoughts????


Title: Re: Mrs. Pacman help
Post by: P-feif on November 11, 2014, 10:07:54 pm
O.k. I'm trying to find time to get back to this thing but I have a question for you guys. Take a look at the picture above. Notice how the red shadows are only on part of the maze? Notice how some of the shadows are mirror images of only some of the maze shapes? Notice how the ghosts and Mr. Pacman DON'T have any red shadows? I would think that if this were a convergance issue or a back tracing issue that the red shadows would be everywhere and not just in certain select spots. I'm wondering if this is possibly a board issue?  ???

Anyone???


Title: Re: Mrs. Pacman help
Post by: P-feif on December 04, 2014, 06:14:28 pm
O.k. I haven't been able to work on the Mrs. Pacman game in a long time and I knew that it needed to have the tube rejuvinated so I called a shop near my house called Big Toys and talked to them about it. The last time I worked on it I had gotten the red colors on the monitor to work again (red did not work when I bought it so I rebuilt the monitor boards), but the red colors were weak. Today I pulled the monitor out of the game and dropped it off at Big Toys to be rejuvinated. They just called me a little while ago and said that they got it working. At first when they ran the tests on the picture tube EVERYTHING tested bad, and they thought for sure the picture tube was dead, but their tech wanted to try to work on it and see what he could do with it. They found that not only was the red gun weak, but so was the green gun too, the blue gun was working o.k-ish. Also they found six shorts in the tube. Well their tech managed to rejuvinate all three color guns and in some sort of miracle he was able to fix ALL six shorts. They said they couldn't believe that it came out so good and now when they test the monitor it has great color, great focus and great convergence. Best $40 I ever spent! I'll get my monitor back tomorrow and I'll post pics and maybe a video when I put it back together. Thanks for the help you guys have given me. I have more to work on but I think that I have the monitor sorted 100% now.



Title: Re: Mrs. Pacman help
Post by: iankellogg on December 05, 2014, 08:35:26 am
$40 seems really cheap honestly. That is amazing such a place exists near you.


Title: Re: Mrs. Pacman help
Post by: P-feif on December 05, 2014, 06:36:51 pm
Yes I'm fortunate to have them near by.

I got the monitor back and installed it. The color and focus are incredible! However I still have that weird red shadowning around the maze pieces. It's no where else either, only the maze. Not the ghosts, or Mrs. Pacman, or letters/numbers. I'm thinking this has got to be a PCB issue. So now that the monitor seems to be working I'm going to try to figure out some issues with the PCB and see if I can fix them. If not I'll be looking for someone that can fix Mrs. Pacman boards. Possiblely that shop, but I really want to take a crack at it myself and see what I can learn.


Title: Re: Mrs. Pacman help
Post by: P-feif on December 06, 2014, 05:31:12 pm
O.k. so now that the rejuvination has been done I needed to do some final adjustments. I found by turning down the red cut off I can get rif of that red shadowing that I thought was a PCB problem. Turns out that even after the rejuvination the red gun is still sort of week but I was able to find a nice "sweet spot" where I had almost not red shadowing but just enough red that eveything would show up. I wish the red gun was just a touch stronger as I'd be able to see things like red letters and red dots just a tiny bit better but this seems to do it pretty good. I really don't think it can get better without a better tube or have new guns installed in this tube, and good luck finding someone to do that. So for now this is it. As good as it's going to get and it's pretty darn good. It's WAY better then the junk pile it was when I first brought it home with no red and week colors colors all around, with poor focus. Next up will be some PCB work, new filter caps, touch up solder joints, maybe get rid of the speed up. Replace the PCB connector, and fuse blocks. Fix the sound issue (might just be a bad speaker). Fix the "by passed" safety switch on the back door, and some minor cosmetic work, like lights and coin door, and overlay, etc, etc, etc........ At least the monitor is done until the next time it dies.

https://www.facebook.com/video.php?v=10203243780672357&l=5579228273544650768 (https://www.facebook.com/video.php?v=10203243780672357&l=5579228273544650768)

Thanks for all the help and advice. I would have had a very difficult time doing this with out you guys. John thanks for the inspiration. I wouldn't have even tried anything like this if I hadn't found your Youtube channel and watched your videos.


Title: Re: Mrs. Pacman help
Post by: P-feif on December 18, 2014, 08:03:19 pm
Sorry I just realized that the video I posted above was set to private. I set it to public so you guys can see it.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 04, 2015, 01:18:13 pm
O.k I just ordered this stuff from Bob Roberts....


Mrs Pac Man axial capkit (PCB).
 
Fuse block with 22/44 molex connector with split pins.
 
Mrs Pac Man crystals
 
Mrs Pac man centering grommet for the control stick.
 
Let's see where that takes me now.

I also need to look into the high score save kit with attract that John used on his Pac Man.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 04, 2015, 07:02:11 pm
O.k. I got a response back from Jason Souza that says....

Adding Slava to the email, I believe he still does these kits.


Good luck
Jason


This should be interesting.  :-\


Title: Re: Mrs. Pacman help
Post by: John's Arcade on January 04, 2015, 07:46:32 pm
Slava sells the kits on ebay. I got mine from there. Or you can buy direct.

http://www.ebay.com/itm/PAC-MAN-MS-PACMAN-High-Score-Save-Kit-/271416951546?pt=LH_DefaultDomain_0&hash=item3f31b602fa


Title: Re: Mrs. Pacman help
Post by: P-feif on January 05, 2015, 08:22:53 pm
Thanks John. I did get a reply from him and he wants me to send him a picture of my PCB. So I'll send it to him tonight when I get home from work. Hopefully with the hack done to my PCB it will still work (no ribbon cable or daughter board).

I gotta get caught on all the video's that you posted over the Christmass break.


Title: Mrs. Pacman help
Post by: jtslade on January 18, 2015, 12:25:41 pm
Do you have a great soldering iron ?


Sent from my iPhone using Tapatalk


Title: Mrs. Pacman help
Post by: jtslade on January 18, 2015, 12:27:50 pm
Very cool! Good work


Title: Re: Mrs. Pacman help
Post by: P-feif on January 20, 2015, 08:24:49 pm
No I have a el-cheap-o soldering iron, but I'm getting by with it. I may upgrade to a nice Weller one of these days.


Thanks, not bad for a beginer huh?  ;)

And yes the kit will work with my board hack, I just have to jumper the scratched off traces.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 26, 2015, 05:39:31 pm
Well I started round 2 of repairs.....


(https://scontent-a-ord.xx.fbcdn.net/hphotos-xaf1/v/t1.0-9/10930861_10203583748051329_6349597072123741884_n.jpg?oh=d28ef7066c3afb348617752cfdb24747&oe=5566FD39)


Title: Re: Mrs. Pacman help
Post by: P-feif on January 31, 2015, 10:02:02 pm
Had time to do a few more little things today.

PCB edge connector from Bob Roberts.

(https://scontent-b-iad.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/r270/10383561_10203615191357392_7482033628127547494_n.jpg?oh=b5dadbdec46926d47ff821f93816bc0e&oe=5523E83B)

Fuse block from Bob Roberts. I noticed that there is a second fuse block. Think I should change that one too because it didn't come with the kit.

(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-prn2/v/t1.0-9/10612637_10203615191317391_8479500016520937130_n.jpg?oh=0562ba1e73ca3ef30720ac9a06451e75&oe=55536E8C&__gda__=1431894287_7095f9c5684520ddc94daf051067f779)


Title: Re: Mrs. Pacman help
Post by: P-feif on February 07, 2015, 06:07:21 pm
O.k. just got the high score save and 4 in 1 pac kit installed and had a scrambled screen. I noticed when I put the Video Ram Addresser back in that the extension socket that came with the kit was very loose feeling. I wiggled the VRA and extension socket and boom, I got an image however the picture has the top half on the bottom and the bottom half on the top. I'm pretty sure that the extension is just a pile of junk. Anyone know where I can get a better extension socket.

I did JUST sent an e-mail to Slava and I'm waiting for a reply from him. In the mean time if any of you guys can help I'd really appreciate it.


Title: Re: Mrs. Pacman help
Post by: P-feif on February 09, 2015, 04:51:06 pm
O.k. Got the Video Ram Addresser figured out. Problem solved but now I need to get this thing to go into the set up screen. Can get the set up screen to work because there is an issue with the test switch. Anyone have a wife schemattic for it. I have the original manual for Mrs. Pac Man and it has all the schmatics in it however I can't find anythin about the test switch. Also inside the coin door there is a red button just above the test switch. I have no idea what the red button is for. Anyone?????



Edit: O.k. looking at the schematic I finally found the test switch. There are some cut wires on the coin door and the slam switch is missing. I'll have to look into it when I get some time. Still don't know what the red button is for.




Title: Re: Mrs. Pacman help
Post by: P-feif on February 09, 2015, 08:57:10 pm
Did some poking around on line. Credit button. Seems neither are working. I think when I get home I'll pull the coin door and take a closer look at the harness. The harness from the connector into the cabinet looks intact so I think (I hope) all the wire butchering is right at the coin door.


Title: Re: Mrs. Pacman help
Post by: P-feif on February 10, 2015, 07:09:25 pm
GOT IT! I cut all the tie wraps off of the coin door harness and started tracing wires and comparing the harness to the schematic. All of a sudden the schematic made sence and I found the problem. The wires from the test switch are routed through the slam switch, which is missing. I found the ends of the wires and according to the schematic there is a red wire on one of the coin mechs that acts as a common ground that come off of one side of the slam switch. On the other side of the slam switch is a blue wire that goes up to the test switch. When the test switch is in the test position power should go through the blue wire then the slam switch and then the red ground on the coin mech. I tied the blue wire to the red ground on the coin mech and WA-LA I had access to the set up menu.

Now if I can just figure out how to get it to boot to Mrs. PacMan instead of the game menu I'll be all set (might no be a possibility, got an e-mail sent to Slava to ask if it can be done).

We'll see, If I don't like the 4 in 1 kit I can always convert it back to Mrs. Pacman again. I used a sharpie to mark everything on the PCB so I can put it back the way it was if I ever want to.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 08, 2015, 03:53:49 pm
I'm have a problem with a distortion in the sound. I've looking over the diagram/schematic and found some capacitor that I thought I'd change via the shotgun approach. One of them is a tantalum capacitor. When looking at the board more closely I found a trace on the back of the board that bridges the tantalum capacitor to one leg of a nearby chip and the trace has been scratched off. I'm wondering if this might be the issue??? Should I bridge the two pins with some solder to repair the trace? Can some of you with more skill then me please weigh in???? Here's some pictures of the board/cap/trace/schematic. Pen is used as a pointer.

(https://scontent-lga.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/10406345_10203829528755693_2422964156215206405_n.jpg?oh=e059a19c84b2d38b4e0e9164948f130b&oe=557B33E7)

Cap at C49 front of board
(https://scontent-lga.xx.fbcdn.net/hphotos-xpf1/v/t1.0-9/10367788_10203829528635690_14266326913588358_n.jpg?oh=7521fd843761dce06466d85d29d7c158&oe=5578C915)

Scratched off trace on the back of the board. The pin to the right of the pointer is one leg of the cap, pin to the left of the pointer is one leg of a chip. I believe it is on the schematic as a gate called 11A (Note 11A is listed twice on the schematic).
(https://scontent-lga.xx.fbcdn.net/hphotos-xpf1/v/t1.0-9/11025193_10203829528675691_2491353791718634119_n.jpg?oh=fb11938219e97ea55a793a410301f541&oe=558448FD)


Title: Re: Mrs. Pacman help
Post by: VertexGuy on March 08, 2015, 03:56:38 pm
I wouldn't be able to see that scratch, the board would be at Eldorado by then lol.
Connect them... it don't work... scratch it back off.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 08, 2015, 04:03:34 pm
Thanks I'll try it.

Also I have a replacement cap for it but nothing on the board or old cap indicates + or -. Any idea which way it goes.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 08, 2015, 06:17:57 pm
O.k. I bridged that trace. Made no difference at all. Upon inspecting the board a little closer I found that on the parts side there is another trace that connects those two pins. So I really starred at the schematic and figured put which is + and - for that tantalum cap and I replaced it. Still no change. The sound issue is as if the sound is breaking up at times. You can really hear it during the intermission when it plays some music. The more base sounds really make it act up. The more high pitch sounds it almost doesn't act up at all.

Next to the tantalum cap is a mylar cap. I bought a replacement for it but it's huge and I don't think it will fit on the board very well so I'm not going to use it. Also there is a great big heat sink covering these two caps. It was very hard for me to replace the tantalum cap. I bent the heat sink out of the way somewhat being careful not to crack to solder that hold it because it also hold a chip in that location too (the same chip the I "think" has the 11A gates). Since everything on this board is soldered on both sides trying to get the solder out of the holes with that heat sink in the way was a real chore. In the end I inadvertently bridged the two pads on the parts side and could not get my solder sucker to remove it all, even after adding a little solder to give it something to suck up. I ended up using the solder sucker to remove what I could and then I carefully used a sharp pointy tool to scrape a little gap down the center of the two legs/pads.

Just played a quick game and it still sounds the same. I know it's not a ROM issue because I removed all the ROM's and replaced them with a 4 in 1 kit from Souza on-line. I had the same problem with the original ROM's and still have it with the 4 in 1 kit. There is something going on with this board, I just can't figure it out.... yet.

Any idea's guys????


Title: Re: Mrs. Pacman help
Post by: P-feif on March 23, 2015, 08:54:01 am
Still trying to trace down the sound distortion issue. I've replaced an electrolytic cap (that doesn't come in the Bob Roberts axial cap kit) and a tantalum cap, plus about 5 or 6 resisters trying the shotgun approach. Still have not fixed it. I did buy a crystal for it, not for this problem but only because it was $1 and I thought I'd just hang on to it. Looking at the schematic I don't see any real big interaction between the crystal and audio processor but I'm wondering just what the crystal is used for? I remember playing around with my friends RC cars when I was a kid and I remember using crystals to control the output frequency of the transmitter/controller and you also had to have a matching crystal in the receiver. So what does this board need to use a frequency for????? Part of the clock? It seems to directly interact with the Z80. If any of you know please if you could explain it.

(I did plug an old car speaking into this thing to see how it sounded, the Ms. Pacman audio amp did not have enough power to really drive the car speaker so it sounded really tinny but you could hear the same distorted sound as with the original game speaker so I don't think my speaker is bad)


Title: Re: Mrs. Pacman help
Post by: iankellogg on March 23, 2015, 09:13:22 am
well to start with, the crystal is the main clock for the entire board. there is no audio processor per say in pacman. How it works is the z80 tells the audio chip to play a certain sample. the audio chip is kind of like a eprom with a clocked output. the output goes through a R-2R ladder dac to generate the analogue signal of the sound. It goes through the amp and out to the speaker. I don't know what kind of distortion you are talking about so I can't say for sure whats the problem but audio is both simple to work on a pain to fix.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 24, 2015, 09:50:50 pm
Thanks Ian. Well the board runs fine so I'm guessing the crystal is fine.

Maybe I should fineally make a youtube account so I can post a video and let you hear it.

Basically the sound sort of brakes up. I don't know it just doesn't sound right and the only way for anyone to understand it would be for me to post a vid. Can you guys see the vids that I've posted off of Facebook?


Title: Re: Mrs. Pacman help
Post by: iankellogg on March 24, 2015, 09:52:49 pm
If the video is set to public we can


Title: Re: Mrs. Pacman help
Post by: P-feif on March 25, 2015, 03:19:58 pm
O.k. Then I'll try to post something that demonstrates the sounds issue when I get home from work tonight.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 26, 2015, 12:22:39 am
O.k. here's the video. You can hear how the sound is just not right. Sometimes you can hear the base sounds break up really badly but not so much in this particular video. Also this machine was doing this when I first bought it and through all the repairs that I've done nothing has changed the sound issues one bit. Note that I have installed a Souza 4 in 1 kit, the sound issue was there with the original rom chips and is still there with the Souza kit. I have also changed the tantalum cap at C49, the Electrolytic cap at C48, the resistors at R5, Rk96, R95, R94, R93, and R92. I have the ceramic caps for C46 and C47, and a mylar cap for C50 although I have not installed them (yet). I have not tried to change any of the IC's yet mostly because I don't have a logic probe and am not sure how to check them although I could just change them all via the shotgun approach. Also I have install a high score save kit (Souza), I did a full axial cap kit from Bob Roberts and also installed an edge connector repair kit from Bob Roberts along with a wire harness edge connector also from Bob Roberts, along with the 4 fuse, fuse block on the bottom of the cabinet. I'm also not opposed to the idea that this could simply be a bad speaker.  :P



https://www.facebook.com/video.php?v=10203943503564992&l=8181059334743831816

Sorry I could not figure out how to post the video with tags on the link so I hope the link works. If anyone would like to show me how to post the video I'm more then willing to try to learn it.


Title: Re: Mrs. Pacman help
Post by: iankellogg on March 26, 2015, 10:19:37 am
I think it might be a bad speaker. Try turning the volume down as well, see if that helps. If you replaced C51 and C48 you should be fine with the board.


Title: Re: Mrs. Pacman help
Post by: P-feif on March 26, 2015, 07:36:07 pm
Alright well I did find a speaker on Mike's arcade web site for a good price so I guess it can't hurt to buy it. If it doesn't work then I'll let you know. Thanks Ian.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 02, 2015, 11:00:45 pm
Replaced the speaker. Still the same problem. I did measure the voltages at the two big filter caps on the PCB and it was 8.2 volts. Sounds a little high to me. I'm going to go dig on the web but shouldn't that either be 7 volts or 5 volts? I don't know that that's my sound issue but it's still something that I need to look into. At any rate I still have a sound issue. Please see my video that I posted above.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 02, 2015, 11:12:00 pm
Just read this on the lawnmowerman web page....


Next read DC voltage from ground to the top end of R52,  about 12 Volts DC.  Missing voltage here would indicate open R52.

Next read DC voltage from ground to BASE of transistor on Heat Sink, should be about 5 VDC.

Low Voltage 2~3 VDC when measured at C2 or C3.  Resistor R53  4 Ohm 10 Watt gets warm.  Measured Voltage from Ground to the Base pin of  Q6 ( D44MV4 on the big heat sink, may also be a TIP 31 or ECG 377) Shows ~ 8 VDC.

Replace D44VM4.  Be sure to install mica insulation & plastic sleeve on the the bolt too.

~ Note the pins on Q6 are marked on the board or refering to the above picture top to bottom

B) ase
C) ollector
E) mitter


Looks like a transistor? I'm guessing it regulates voltage some how?


Title: Re: Mrs. Pacman help
Post by: P-feif on April 11, 2015, 10:34:39 pm
Ok I've done a little measuring with my multimeter and here's what I've found. Voltage at C2 and C3 is 8.2 volts, should be 5 volts. Volts at R52 either 15.8 and/or 16.3 depending on wich end is considered the top end of the resister (lawnmower man web page says to measure it at the top end of the resistor), should be 12. Voltage at the base leg of the voltage regulator is 5.6, should be 5. Resistor R53 gets hot to the touch.

So what do you guys think? Change the voltage regulator? The lawnmower man web sight says that you may find a TIP31 transistor in place of the regulator (original is a D44MV4 3 pin voltage regulator). So can I replace it with a TIP31 transistor? Or should I track down a 5 volt regulator equivalent to the original.




Title: Re: Mrs. Pacman help
Post by: thegleek on April 14, 2015, 08:48:13 pm
Ok I've done a little measuring with my multimeter and here's what I've found. Voltage at C2 and C3 is 8.2 volts, should be 5 volts. Volts at R52 either 15.8 and/or 16.3 depending on wich end is considered the top end of the resister (lawnmower man web page says to measure it at the top end of the resistor), should be 12. Voltage at the base leg of the voltage regulator is 5.6, should be 5. Resistor R53 gets hot to the touch.

So what do you guys think? Change the voltage regulator? The lawnmower man web sight says that you may find a TIP31 transistor in place of the regulator (original is a D44MV4 3 pin voltage regulator). So can I replace it with a TIP31 transistor? Or should I track down a 5 volt regulator equivalent to the original.
Hah! Wow! I'm having voltage issues with my Ms Pacman too! Maybe one day we can set something up to compare notes on fix both our games! We have an arcade group (small - 3 people now) that meets after 6pm on Monday's. But anyways, lemme know your thoughts and obtain permission from homeowner to see if this can be arranged...


Title: Re: Mrs. Pacman help
Post by: P-feif on April 14, 2015, 09:37:19 pm
Well I work afternoons so it gets pretty hard to do things like that but I would love to talk arcade games with you guys sometime.

For now look on the lawnmowerman web site. They have good information on the pacman and ms pacman games.


http://lawnmowerman.rotheblog.com/


Title: Re: Mrs. Pacman help
Post by: thegleek on April 14, 2015, 10:53:02 pm
Well I work afternoons so it gets pretty hard to do things like that but I would love to talk arcade games with you guys sometime.

For now look on the lawnmowerman web site. They have good information on the pacman and ms pacman games.

http://lawnmowerman.rotheblog.com/
Hah! I've been on that site for hours & hours. Great reference! We also started a local (to us at least) blog with our adventures: http://gameaholix.com/


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 15, 2015, 07:29:41 am
Ok I've done a little measuring with my multimeter and here's what I've found. Voltage at C2 and C3 is 8.2 volts, should be 5 volts. Volts at R52 either 15.8 and/or 16.3 depending on wich end is considered the top end of the resister (lawnmower man web page says to measure it at the top end of the resistor), should be 12. Voltage at the base leg of the voltage regulator is 5.6, should be 5. Resistor R53 gets hot to the touch.

So what do you guys think? Change the voltage regulator? The lawnmower man web sight says that you may find a TIP31 transistor in place of the regulator (original is a D44MV4 3 pin voltage regulator). So can I replace it with a TIP31 transistor? Or should I track down a 5 volt regulator equivalent to the original.

IF the big resistor in the upper right hand corner is getting really hot then your voltage regulator is dead and needs replaced.

Edit. By voltage regulator I mean the 3 pin transistor that is on the heat sink. The voltage regulator is a 4 pin device below the heatsink. It most likely does NOT need replacing.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 15, 2015, 04:37:47 pm
Ok I've done a little measuring with my multimeter and here's what I've found. Voltage at C2 and C3 is 8.2 volts, should be 5 volts. Volts at R52 either 15.8 and/or 16.3 depending on wich end is considered the top end of the resister (lawnmower man web page says to measure it at the top end of the resistor), should be 12. Voltage at the base leg of the voltage regulator is 5.6, should be 5. Resistor R53 gets hot to the touch.

So what do you guys think? Change the voltage regulator? The lawnmower man web sight says that you may find a TIP31 transistor in place of the regulator (original is a D44MV4 3 pin voltage regulator). So can I replace it with a TIP31 transistor? Or should I track down a 5 volt regulator equivalent to the original.

IF the big resistor in the upper right hand corner is getting really hot then your voltage regulator is dead and needs replaced.

Edit. By voltage regulator I mean the 3 pin transistor that is on the heat sink. The voltage regulator is a 4 pin device below the heatsink. It most likely does NOT need replacing.

Thanks Ian. I did see the 4 pin and knew that it was not a transistor. So the BIG heat sink with the 3 pin transistor really is a transistor? Will a TIP31C work, I have one from Bob Roberts, but was going to look deaper into it. I can replace it now if the TIP31C is o.k. to use.

By the way did you mean the big resistor in the upper left hand corner? Right above the transister on the big heat sink? That's the one that's getting hot, really hot.


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 15, 2015, 06:12:32 pm
I think a tip is fine replacement.  Yes I am talking about the resistor above the heatsink.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 15, 2015, 07:22:33 pm
Cool! I'll try to get it replaced in the next few days. Thanks Ian!!! ;)


Title: Re: Mrs. Pacman help
Post by: P-feif on April 17, 2015, 03:02:26 pm
Alright I replaced that transister on the big heat sink with a TIP31C. Got it done this morning and now...... nothing, no change. All my voltages are still screwed up (see my post above) and the sound is still messed up. What do you think Ian? The 4 pin volt regulator???

I'll say this, I don't think there's much left to replace.


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 17, 2015, 03:37:44 pm
thats all i can think of left.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 17, 2015, 05:40:09 pm
Alreighty then! I'll track one down and see what happens. I suppose that one of the ceramic resisters could be weak but to be honest I haven't studied the prints enough to know how power is flowing through the circuite so I really don't know how those resisters contribute. So the voltage regulator it is. I'll keep you up on things. Again thanks for your help Ian.


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 17, 2015, 06:16:19 pm
The resistor should never get hot.  The only reason it is there is to keep the board from blowing up when the regulator fails.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 17, 2015, 10:24:26 pm
Hmmmm, so I probably shouldn't turn it on much for the moment?  :-\


Title: Re: Mrs. Pacman help
Post by: P-feif on April 19, 2015, 09:42:05 pm
Looks correct to me. Good place to buy it from? Any better places that you guys would like to recommend?

http://www.mikesarcade.com/cgi-bin/store.pl?sku=VR953


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 19, 2015, 09:48:59 pm
i think thats the one. I can't check atm.


Title: Re: Mrs. Pacman help
Post by: P-feif on April 20, 2015, 08:07:31 pm
Anyone ever order from Twisty Wrist Arcade? Looks like they have the same part for less. I can't find any part number even close or that will cross reference on Bob Roberts site, which is a shame because I'd much rather get my parts from him if possible.


Title: Re: Mrs. Pacman help
Post by: iankellogg on April 20, 2015, 08:08:53 pm
twisty wrist is good stuff


Title: Re: Mrs. Pacman help
Post by: P-feif on May 05, 2015, 02:47:53 pm
Got around to changing that voltage regulator today. With the old regulator I had 8.2 volts. With the new regulator I have 8.18 volts. Hmmmm. Something is wrong here.


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 06, 2015, 07:57:15 am
i'm not too sure what to say right now. if you have replaced the voltage regulator IC and the main transistor i dont know anything else off the top of my head.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 06, 2015, 09:41:34 am
Is it possible that one of the leg to the regulator or the transistor is grounded/shorted somewhere and I'm just missing it.

I really thought that I had fixed it when I replaced those parts too.  :-[

Thanks for all the help Ian. I'm sure we're on the right track here.....


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 06, 2015, 09:49:48 am
Where are you measuring the voltage on the board? are you using an IC or are you using the two big caps in the upper left.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 06, 2015, 04:49:52 pm
Two big caps in the upper left.


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 06, 2015, 05:07:03 pm
those should be above 8V. measure on a chip. or one of the smaller caps in the middle of the board.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 06, 2015, 07:19:43 pm
Doh! Well o.k. then. If I get 5 Volts at the chip then I guess that means that I still have a weird sound issue to fix. I was really hoping to fix it with this voltage things. I'll look at it sometime over the next few days. Any particular pin or should I just look at the schematic?


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 06, 2015, 07:25:08 pm
If you have replaced all the caps in the audio section i will have to think about what it could be.


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 06, 2015, 07:30:23 pm
Okay i went back and watched the video. There is hardly anything wrong with that sound to me. It sounds a bit off but maybe try turning the volume down quite a bit and see if that improves it. Its certainly not like what i normally see when the audio is going bad.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 06, 2015, 08:57:54 pm
I have turned it down and it does the same thing. It breaks up, just quieter. I've tried other speakers and I can hear the same issue. I even went to a local arcade shop and listened to theirs and it is WAY better. I could live with it but I'm a perfectionist and I'll chase it until I don't have a way to chase it.  :P

I've noticed a few "things" screwed to the side of the cabinet that I haven't been able to identify (or at least I haven't looked at the wire diagram to see what they are). Any chance that one of them might be a filter of some sort?


Title: Re: Mrs. Pacman help
Post by: P-feif on May 27, 2015, 04:30:16 pm
Well with the change in whether I've been working on outdoor projects so the Mrs Pacman has gone on the back burner for now. However it does get turned on and played. This morning I didn't have time to get into my outdoor projects because I had things to do with my son and his preschool class, but i did have a few minutes to fix a few small things that have been sitting on my work bench and while I was there I turned on the Mrs Pacman and played a few games. The last one ended with the PCB flipping out. I was having this trouble awhile back and thought that I had fixed it. I installed and new 4 fuse, fuse block, I installed and new PCB connector on the wire harness, and I also installed a new PCB edge connector repair kit on the PCB and reflowed some stuff on the board along with a new PCB axial cap kit installed. So today when it went nuts I was surprised as it's been playing stable since around Christmas time. Any ideas what else I should be looking for please feel free to comment. Not sure when I'll get to it but I'll keep any ideas in the back of my mind and I can always refer back to this thread too. Thanks....


Title: Re: Mrs. Pacman help
Post by: iankellogg on May 28, 2015, 07:59:56 am
well videos always help. but general things apply as well. check AC voltage to the PCB. Check DC voltage at an IC. check AC voltage at theIC and make sure it is less than 200mV at the IC. Consider putting it in test mode per the manual .


Title: Re: Mrs. Pacman help
Post by: P-feif on May 28, 2015, 04:50:51 pm
Well I can check the voltages but it's modified with a Souza 4 in 1 kit so the test switch only opens a set up menu now. No more test mode. I'll do some poking around hopefully soon, and let you know what I find.


Title: Re: Mrs. Pacman help
Post by: P-feif on May 30, 2015, 12:20:28 pm
Did some poking around. Found that the wire harness has a white connector a few inches before it goes into the black PCB edge connector. The pins in the white connector seemed a bit loose. I found that the male side of the connector the pins have small slots down the center of the pins and so they could be spread open a bit with a very small flat blade screw driver, so I spread them open. The connector felt nice and tight after that. Played about 8 or 10 games and made sure to be a bit rough on the game to see if I could get it to reset. Nothing... It played perfectly.

Now back to that weird sound issue. I think I need to buy a logic probe and learn how to use it.


Title: Re: Mrs. Pacman help
Post by: P-feif on October 24, 2015, 08:55:16 pm
So I haven't worked on this thing since last Spring. Back then I noticed that my high score save kit was filling the tables with garbage so I contacted Slava who sells the kits and he wanted me to send him my PCB so he could take a look at it. Well a few days ago I finally got a break from all my Summer time projects and I sent him my PCB. We'll see what happens next.

Next up, restore the control panel and coin door.  ;)


Title: Re: Mrs. Pacman help
Post by: P-feif on November 02, 2015, 10:06:05 am
Just got this back from Slava....

Hi Tom, sorry for taking so long, but work has been a bitch this week.  Anyway, I think I finally fixed your sound problem.  Without getting into all the technical, your sound amp needed to be replaced.  I also think the issue where the high scores were getting corrupted was because the VRA daughterboard, which sits above the HSS board was not sitting in the socket properly. Someone had replaced the original socket at some point with a very odd one. I replaced that socket and added some risers so that the VRA sits properly. I also cleaned up all the wiring in the back from the previous hack.

 

Just going to let it run the rest of the day and see if anything odd happens. I don’t expect it to.


This guy has been great to deal with. I'd highly recommend him for help with your Pac Man and Ms Pac Man games.

It will be nice to get this PCB back and in the game. This "should" mean that I'm don't working in the back of this game so I can do the control panel and coin door and then move on to my Space Invaders game. I won't restore the cabinet for the Ms Pac Man any time soon. Maybe in the next few years. I can live with the "character" that is has for now. I'd rather spend my money collecting a few more games and then restore the cabinets one at a time.

Thanks SLAVA!


Title: Re: Mrs. Pacman help
Post by: P-feif on November 05, 2015, 01:08:11 am
Well I got the PCB back from Slava and he got the high score save kit fixed. Also he worked on my sound issue. The audio amp (chip, top right corner of the PCB) had to be replaced. It sounds awesome!!!!!!! I love it!!!!!!!!

Right now the game is on and I'm going to leave it on for a few hours just to make sure that the high score tables don't fill with garbage but I'm pretty confident in Slava's skills so right now I think it's fixed!!


Title: Re: Mrs. Pacman help
Post by: P-feif on January 05, 2016, 10:03:33 am
I'm trying to get the coin door straightened out. If anyone can post a pic of the inside of their (unmolested) Ms. Pacman coin door it would be of great help to me. I'm having some trouble understanding the wire schematic vs the actual door. I'll post some pictures. Someone has butchered the wiring of this coin door at one point.

Here's a picture of the back of the coin door.

(https://scontent-ord1-1.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/12507184_10205552063537986_4068321059458333865_n.jpg?oh=144faeca20a68be58167e81b767dfccd&oe=571524D7)

One the left lower corner you will see two red wires and one blue wire. The schematic shows a red and blue going to the slam switch, so do both reds to the slam switch or just one? On the right side there is an orange wire with a "pin" on the end of it. I believe that it should go to a two pin connector (kind of like the one with green/b and light blue/r wires) and I also think that someone removed that connector and the light blue wire that use to go to it so it should be a connector with orange/b and light blue/r. That's my guess.

The schematic show that both connectors with green/b - light blue/r and the orange/b - light blue/r should be plugged into some thing called a credit bypass pc. I don't know what a credit bypass pc is. Any of you know? Or where is should be mounted?

Any help appreciated. I just want to get the coin door working as it was intended to work.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 06, 2016, 11:28:32 am
One more thing I forgot to post about this coin door. The schematic show a 100 uf capacitor on the slam (tilt) switch. Is it really suppose to be soldered to the tabs on the switch or is it located somewhere else, like on the PCB. I need to know that before I solder a capacitor to the switch and put power to it. Don't want to fry anything.


(https://scontent-ord1-1.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/535060_10205557620516907_2461814559077279107_n.jpg?oh=6162bfc43eee19455e5bfef82bc5ff9b&oe=57423695)


Title: Re: Mrs. Pacman help
Post by: iankellogg on January 06, 2016, 11:29:50 am
according to the schematic that is soldered to the terminals of the switch


Title: Re: Mrs. Pacman help
Post by: P-feif on January 06, 2016, 01:52:04 pm
Thank you Ian, if there is anyone that I trust... That's how I'll do it then. Any chance you know what a credit by pass is??? There's a few connectors that are supposed to plug into it. Whatever "it" is.


Title: Re: Mrs. Pacman help
Post by: iankellogg on January 06, 2016, 01:57:51 pm
The credit bypass board is how pacman sets the pricing. If you only plan to do 1 credit = 1 quarter or freeplay you dont need it.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 09, 2016, 10:53:52 pm
O.k. then I got it done and it all works. Thanks Ian! Maybe I'll look for a credit bypass board just to have it. I did get the coin mechs working, the coin counter works, the test switch works, the credit button works, I even set the 4 in 1 kit to 1 coin 1 play and tried it and it coins up just fine. Set it back to freeplay for my use. For now this thing is done at least until I decide to restore the cabinet, which most likely won't be for at least a few years. Thanks for everyone's help and advice! Next up Space Invaders!


(https://scontent-ord1-1.xx.fbcdn.net/hphotos-xfa1/v/t1.0-9/12508820_10205576960480394_3056983020779176700_n.jpg?oh=9b7b1ffcb48df40182ae0a2f6472fe05&oe=5709EAF3)


Title: Re: Mrs. Pacman help
Post by: KennyL on January 11, 2016, 08:28:56 am
Congrats on getting it all working well.

Side note, I know it's none of my business but that is a large variety of laundry detergent/fabric softener.  Heh.


Title: Re: Mrs. Pacman help
Post by: P-feif on January 16, 2016, 03:46:11 pm
My wife does that extreme couponing. LOL! Right now they are buy 2 get 3 free and she has a coupon so.......