u/4410th

I don't know if it's me, and I've been banging my head against this wall for hours but I can't get much of anything to load. Fresh install with update-all/bioses. Arcade works as it should and the bios files are in the correct folders. The only core I've got working is the megadrive running Sonic 1, of the 10 other games I tested only that and the test program work. The rest flash some kind of brief pattern on the screen for one frame then stay black. Board has the alliance memory soldered, I'm running a memtest at 160mHz, it seems to be passing and I don't know what else to try. Any help would be amazing.