Well even if something is stuck high, the only way to fix the issue would be to replace the chip provided there are no broken traces, which I haven't seen any. Am I right? If this is the case I think I'm just going to order a replacement board. I think I might order the replacement board anyway and just sell this one back to the guy I bought it from. He can fix it, just not in time for Christmas.
Edit- I'm trying this board repair one last time. Out of curiosity, what would happen to an MVS board if you booted it *without* the top board attached? Would it produce the same garbage screen? Because mine did, only the system did not reset like it did with the top board attached.
Edit again - added pics. I also checked each chip to make sure they were getting power and everyone of them came back at 5.03v.
Edit a third time - breakthrough! after doing what appears to be absolutely nothing, having the top board disconnected and testing the bottom boards chips for their voltage, the board started the test cycle! I finally got a visible error message, and it was as follows:
VIDEO RAM ERROR
ADDRESS WRITE READ
00008000 5555 5500
Now if only I knew where that was, and how to fix it
I might have a great sluggers PCB that I can use for spare parts... maybe thatll have the IC I need? Also, once I put the top board back on, it started the watchdog thing again. HOWEVER, sometimes it doesn't. Sometimes it will do the watchdog thing, other times there will be random garbage on the screen, then a black screen, but no attempted reset - it just sits there. I know this particular post is 9000 words long but heres the basic summary: With just the main board attached, the board goes through watchdog quite rapidly 5 or 6 times, then begins the hardware test before showing the video ram error. Once the other board is attached (with the cart), it just repeats the watchdog every 7 seconds or so.