(2) Mortal Kombat 1 PCB issues

CHALLENGER

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I have two Mortal Kombat PCB boards w/ sounds boards.
I went to fire them up for testing and found that they both work but not flawlessly.

The first board..... This one doesn't have 1 bad rom at all. All roms turn green, and the game runs fine with no glitches.
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However after the board goes through it's rom check it then proceeds to the MIDWAY PRESENTS screen. Then it flickers the main title screen and says.... Revision 3.0 8/31/92 CMOS OK USING DIPSWITCH COINAGE.....
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after it resets itself. (loops this process over and over) If you credit the game and hit start, or just hit start if it's on FREEPLAY. The game will run perfectly fine. I've messed with the dip switches only to find nothing to solve this problem.
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As you can see it works fine other then the reset glitch.....
 
The second board......... does the same exact thing. However this one does have bad roms (4 of them) U95/U96/U97/U98
As you can see in the pics.
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Now you can still run the game if you credit the game, or just push start of a FREE PLAY. Yet when the game starts it has graphic glitches. Again... I've messed with the dip switches to find nothing to solve this problem. I figure the graphic glitch is due to the 4 bad roms on this board.
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Does anyone have an idea what could be causing this? Thanks.
 
board #1 I would encourage reseating the roms first. not entirely sure how the game will play fine if you play it right away. be certain you do this with bubble wrap underneath to prevent the board from flexing. the next step is to check your voltage, Y-unit boards have a +5 and ground test point right next to the JAMMA edge, just touch your meter probes to those 2 points right there with your meter set to 20VDC and see what you got. you ideally want about 5.10 volts. though like I said, I don't know why the game plays fine on free play or if you coin it up right away.

board #2, also reseat the roms. I find it peculiar that that particular section has 4 bad roms in a row... I swear someone had the same problem recently, I just can't remember at all how they fixed it though. basically, the roms might not be bad, it's potentially something silly that's wrong with the board there, since the rom sockets connect in a series. I would visually inspect that area of the board.

dipswitches will have no bearing on any of your problems, so forget about those.

if none of these work, the next step is to start removing roms one by one and making sure there's no corrosion on the chip legs, and that you don't have shit lodged in any of the sockets. do the same for the CPU and any other major components on the boards, though don't try to remove any of the chips from the brown sockets unless you have a PLCC puller... flathead screwdrivers will only break the sockets.

maybe someone else has a similar experience or a better idea, but that's where I'd start. your boards are both revision 3.0 apparently, the one with the bad roms you can also just swap good roms in and see if that makes that go away, that way you'll be for certain it's the roms that are bad, but like I said, I find it weird that it's 4 roms in a row that are all coming up bad.
 
I had one board that on start up it showed a bad block of roms to, when I looked at the solder side all the pins were bent touching each other, you get that especially in boards that have been crushed (had weight sitting on it) be careful what you use to bend them back though you don't want to dig up any traces.
 
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