Simpsons RAM/ROM Test Reset

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I went into the test mode to check everything out. It went into the rom test and it completes.
It does it again but it's upside down on the screen. Says one of the roms is bad. Resets and starts over with the upside down test.
I can't get out of it. It just keeps repeating. The rom is getting proper voltage and everything was working perfectly before I ran the test.
That's what I get for fixing something that ain't broke.
Anyone experience anything like this or know what it could be?Just a rom bad rom?
 
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Which ROM is coming up bad? There is no memory on these things, ie if it sees a bad rom on one pass it isnt going to hold that result and keep repeating it.

What you are seeing suggests that either on of the program ROMs has suddenly developed an error (rare) or the board has suffered a logic fault (very common with Konami boards of this age). If the ROM it is complaining about is not one of the ones in a socket then it will not be the reason the board cannot boot. The other ROMs just hold audio and gfx data, they can be physically missing and the board will boot and run the game, just with large lumps of graphics and sound missing.

If the error is for one of the program ROMs then reseating the ROMs is about all you can do unless you can burn a replacement yourself. If its one of the soldered in ROMs then your board has developed a fault - most likely it was on the edge anyway. Running the test would not cause the fault.
 
Actually - it depends which chip it is complaining about but the following might just fix it. From memory this is relevant if the error message is for the last chip in the test list which is a versioning eeprom on these boards, the following process gets the game to rewrite the data in this eeprom which if corrupted will cause the game to crash over and over at the test screen.

Power off the board, hold down the "test" button located on the PCB near the JAMMA edge and then power up the game while you keep holding the button down. Keep it held down for 20 seconds and then release the button, it will say something like EEPROM Reprogrammed.

If this has no effect then my post above this one is what I would put my money on.
 
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Thank you for both your input. The rom that was going bad I believe was the 12C. I'll try everything out later. I'll come back with the results.
 
Am pretty sure 12c is the EEPROM ( a short 8 pin chip ), the trick I mentioned above with the button on the board should fix it :)
 
I tried the reset & holding the test button down a few times but it is still crashing at the test.
When I got the machine the Test Button on the Coin box was disconnected. I guess I figured out why.

edit:I'm by myself with a mirror and a stick so it's sort of hard. But it went to the EPPROM Test after I turned it on but then it just reset. Am I doing something wrong or is the rom just bad?
 
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I'm by myself with a mirror and a stick so it's sort of hard. But it went to the EPPROM Test after I turned it on but then it just reset. Am I doing something wrong or is the rom just bad?

Did you read this part?

Keep it held down for 20 seconds and then release the button, it will say something like EEPROM Reprogrammed.

If you did not see the Reprogrammed part you did not do it right.

Hope this helps....
 
Reprogrammed has not came up. I hold it for 20 seconds and release and it just goes back the the Test,crashes,and starts over. I've done it a dozen times and nothing has happened. It says the same thing in the manual but it isn't working.
 
I've tried both. Neither are working. It's my luck a common problem with a simple solution doesn't work for me.
 
Most likely is bad Fujitsu logic chip now, it's pretty unlikely the EEPROM is bad, just that the board can't talk to it properly anymore. All you can do easily is to reseated the socketed roms and try the button trick again, beyond that you would need a logic probe and the urge to troubleshoot.
 
I'm at the garage today. I just tried it again and it went into the EEPROM Test without restarting and it said it flashed "bad" and restarted the EEPROM Test.
I'm going to reseat it again and try the restart again. Do you still think it's a bad logic chip? Or is the EEPROM/12c rom actually bad?
 
As I was leaving the shop I wanted to try one last time. Of course it works then. I was an hour late to work because I had to beat the game out of spite. Everything is all good now. Thank you Womble,MKPlayer,and Kb0jjn very much. I greatly appreciate it.
 
Awesome glad you got it working. Womble is the one that deserves the credit for the hold down test trick.

Simpsons is one of my favourite games. I play it pretty often with the kids. Enjoy that working pcb!
 
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