Have a weird one. ROMs are hard to find to verify, but I'm feeling that is probably the issue, but want to throw it out to the hive mind.

Have an Amazon Hunt, System 80A, that appears to boot but not quite. Battery removed, clean board, new 100uf logic cap at the power input, slam switch modified, clean power, passes all tests on NeoDiag80. Reset and clock working right, ready and IRQ working correctly. Had one bad switch matrix chip, z13 replaced.

There's not much activity on many of the address lines, but activity on almost all of the data lines. It boots with zeros in the displays as it should, but is not in attract mode or allows anything to play. Chip select circuitry all appears to be working well with a probe.

Would this be indicative of a potential failure on U2 or U3 or the game ROM? Could the 6502 pass this much test and be bad?

Any ideas appreciated -- thanks!

Yea, slam switch is modified and z26 is correctly sending a high signal off pin 12.

I saw this — couldn’t figure out how to get it to actually download. One of those sites that makes it hard to just download. Is there a left click or something I need to do somewhere?

My computer was trying to block it as unsecured. It downloaded and there now, thanks! I'll verify these images against what I've got and report back.

Don’t see it mentioned as the culprit often, so figured I’d follow up here — z15 was the culprit. It’s a 7432 that controls the switch enables which caused this board to simulate slam switch problems in a strange spot.