Sega System C (14) schematic needed....

Anyone have one by chance? Seems they are made out of unobtanium. MG and Genesis are too different as far as I can tell.

Working on a columns arcade PCB that's having reset issues/halt issues. I purchased it that way and have no background info.

When it arrived, no boot. I noticed it blew the top off of the LS126 logic at IC20. socketed and replaced. BOOTED on my test rig. I want to plug in a controller to play it, and it stalled. Cycled power, this time it made it only to the "say no to drugs screen" and froze. Each time I power cycled it it went less and less. Then stopped booting all together. If I leave it sit overnight, it will boot again. Tried the compressed can upside down trick on logic chips. Nothing worked.

Diagnosis so far is only by logic probe on the reset line to the 68000. When the game boots, its low and goes to high, normal. As it sits, the signal fades to low(ish) about 2v, and the game freezes.

I believe my issues surrounds the LS126 that I replaced as I followed reset to it. But I am at a loss without a schematic.

Hopeful someone might have one, or assist with reset logic on such a board.

Thank you!!

~Tim
 
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