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Title: Pac Man "garbage screen" when powered up? Post by: BR549 Auto Sales on April 04, 2012, 04:11:37 AM Seem as if I saw a repair technique for this common problem on pac man/ms. pac man machines about changing out a bad chip on the board? If someone know if this is true, please let me know and which chip.
Thanks, Daivd Title: Re: Pac Man "garbage screen" when powered up? Post by: channelmaniac on April 05, 2012, 11:32:56 PM Could be a LOT of things.
Common failures on Pac/Ms/Plus machines: Corroded fuse holders in the bottom of the cabinet Heat damaged edge connector - both harness and board Tarnished/corroded/broken pins on the mask ROMs Bad ROM socket Bad CPU socket Bad ribbon cable (Ms Pac) Bent pins or broken pins on the Z80 Sync Buss Card Bent pins or broken pins on the VRAM Addresser Card Bad 2114 RAM RJ Title: Re: Pac Man "garbage screen" when powered up? Post by: BR549 Auto Sales on April 05, 2012, 11:40:42 PM I doubt that anything may be bent, this just happened @ 2 months ago, up until then it was working fine. Edge connector may be a problem but the harness is fine, fuse holders are fine. I will add a picture of both sides of the edge connector later. I can check for corroded pins on the mask roms (where are they located?) can also be the 2114 ram, which I have no way to test. Thanks for the info, gives me a starting point.
Title: Re: Pac Man "garbage screen" when powered up? Post by: channelmaniac on April 06, 2012, 02:53:39 AM Start with the fuse holders, the mask ROM pins, and the edge connector on the board/harness.
The factory fuse holders are brass and not only corrode/tarnish but they also spread open and don't connect to the fuse as tight as they should. You can pick up replacment fuse holders at Radio Shack. I repair Pac boards. Most repairs on those run around $45 to $50 plus shipping. |