I got this game dead.
The MPU shows a "0" on start up, so I think that means it is booting correctly. I press SW2 and "8" appears then goes back to "0"
But the game does not go into attract mode, nothing ever comes up on the display screens (though I can see the dull glow inside the displays which makes me think they are getting power).
-I never hear any sounds, even when I press the SW1 (which I think is the sound test).
-I never hear any coils fire. The GI does turn on.
-All of the test points show the correct voltage.
-I removed and tested every fuse.
I traced out every PIA chip on the MPU according to Clay's manual, very boring, but I found no broken traces. The board has some acid damage, but apparently not enough to break any of the traces.
The game just will not go into attract mode, so I can't do any diagnostic work.
What will make an MPU board "boot", but not have the pin go into attract mode? I am out of ideas about where to look/what to test.
Feel free to list possible things that I claimed to have tested if you think that is the likely culprit. I will check again.