Ms. Pac-Man died - need help diagnosing (have pic)

voltron88x

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[UPDATED] Ms. Pac-Man died - need help (have pics)

Hey guys, I have a Ms. Pac-Man I put over at my brother's office and a few weeks ago it died. I wasn't there but apparently the machine just turned off (no abnormal noises) and then some smoke started coming from the cabinet. It doesn't power up at all now and after having a look-see in the back the only thing I can tell that looks "damaged" is some charring of the monitor PCB. Here's a picture. Do you think this is the culprit, and if so what are my options? FYI, I didn't find any blown fuses on the machine either.

Thanks guys! -Keith

mspacPCB.jpg
 
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You fried your flyback transformer. (The grey thing with the red wire coming out of the top) You should get one from Bob Roberts and replace it. Might be the only thing it needs. The caps look almost new by the pic, do you know if they were replaced recently.

Luke
 
You fried your flyback transformer. (The grey thing with the red wire coming out of the top) You should get one from Bob Roberts and replace it. Might be the only thing it needs. The caps look almost new by the pic, do you know if they were replaced recently.

Luke

Wow thanks for the quick reply Luke! I don't believe the caps have been replaced any time lately, but perhaps a cap kit couldn't hurt either? Do you also know what flyback transformer I should get? I'm pretty sure the equipment is all original. I guess I could ask Bob too.
 
Flyback depends on the monitor.

What monitor is in the game?
 
dont be to quick to judge the monitor chassis as of yet. is the game playing blind or is the machine dead? BTW if it does come down to monitor , that is a GO7 electrohome , get Bobs deluxe kit, has most what you need including fly, HOT and reg
 
dont be to quick to judge the monitor chassis as of yet. is the game playing blind or is the machine dead? BTW if it does come down to monitor , that is a GO7 electrohome , get Bobs deluxe kit, has most what you need including fly, HOT and reg

The fly is definitely dead, look close at the picture and you'll see the shit oozing out of the case, the B+ pot is jacked all the way up to get everything they could out of the fly. Caps are newer and the width coil is newer(not dirty) so this was worked on fairly recently. New fly, new HOT(though rarely bad) new F901 and an R908 resistor(Bob has these) should get you back up and running.
 
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C301 does have a polarized designation on the board but C520 doesn't. I've always stuck the correct NP's in there and ignored the 301 markings.
 
Get bobs deluxe G07 kit and it will fix you right up.
That chassis was recently capped and it stressed the fly enough to make it let go. Happens quite often on these. Thats why most reccomend a new fly on a G07 when you cap them. On my machines I take my chances but if its a job for someone else I will reccomend the new fly.
Good eyes spotting the two polarized caps! I saw the cracked flyback right away but probably would have never noticed those caps.
 
yeah looked at the fly closer , it did pop the case of the fly. also did you notice polarized caps in the place where the NP's should be?

Can you explain to me the significance of the polerized caps (and NP's for that matter)? I was gonna order Bob's Deluxe kit so I'll replace all the caps while I'm at it.
 
non polarized caps do not have a polarity designation to them and generally run at a higher frequency(faster) than polarized. polarized caps are better for energy storage but NP operate more efficiantly. these are in your sync circuit and may cause lack of sync or pic roll when you get this chassis working again. Bobs kit does not include the NP caps , you will have to provide those yourself.
 
You better ask Bob for those NP caps, his kit does not come with them. I ordered a bunch from digikey so I can replace them when I do a cap kit. Bob should have them but doesnt put them in the kit because they usually dont go bad.
 
Hey guys...I ordered Bob's Deluxe G07 kit and replaced most everything (except the width coil and voltage regulators) and the machine still won't power up :( Any ideas? I didn't do the regulators cause they looked like PITA's to resolder and the exisiting width coil looks fine...

Anyways, here's some new pictures...Could the problem lie elsewhere than the monitor board perhaps? Let me know if you need other pictures or more info. Thanks guys!

MsPac 001x.jpg


MsPac 002x.jpg


MsPac 004x.jpg


MsPac 005x.jpg
 
If you unplug the monitor, will it play blind? If it doesn't play without the monitor, you may need to start at square one, check the power inputs starting at the fuse.

ken
 
When you replaced the flyback, did you replace fuse 901 and the HOT? Those usually fail when the flyback goes. (edit) From looking at your pics, that HOT appears to be the old one since the solder joints on it are still dirty. It's probably bad which would explain why your chassis still isn't working. Fuse 901 may also have blown again if the HOT is shorted.

Also I noticed your B+ adjustment is still cranked all the way up. If that's too high your X-ray protection will kick in shutting down the chassis. Start by turning the B+ know so the pointer is in about the 3 o'clock position when viewed from the back of the chassis, (it's the one pot that's mounted flat instead of vertical). Then measure the DC voltage at the end of the large white ceramic resistor on the left side of the chassis. It should be 120v DC when measured on the end nearest the picture tube and the other end of your meter grounded to the metal monitor frame.

Adjust the B+ knob until you get 120v DC, then turn up the screen to see if you're getting raster on the tube.

Also, make sure the game hasn't been switched to test mode inside the coin door, also check the interlocks on the back door too and don't forget the power switch on the top. Sometimes that stuff get's switched off by someone else- you never know.
 
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I'm working on a very similar board. What's an NP? I've been playing with electronics for several years now and perhaps call an NP something different. His board looks very much like mine. (even with the blown flyback)
 
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