Game was playing fine until the other day with it wouldn't boot. Observed the LED locked on at power up.
I assumed problem were the old brown sockets, so I replaced them, but that didn't correct the problem.
There is no corrosion on this board.
I removed all the chips except U6, U9, and U11. Also, replaced U9 and U11 with new chips from PBR and GPE. Still locked on.
The reset circuit appears to be working correctly per the tests in pinwiki.
I have continuity checked every pin on U6, U9, U10, and U11. Didn't find any problems.
I don't have another U6 to try, nor do I have another board to test the 9316-U6 in without changing jumpers. Is there a way to check the U6 any other way?