Left one is supposed to stay on - it's 5v.
Middle one is supposed to flash - its the diagnostic LED.
Right one is supposed to stay on - it indicates you have blanking.
That's all good.

Three bongs at boot indicate a bad U4 sound ROM OS. I'd first try reseating it and see if you still get three bongs.

viperrwk

Oh - you can send a note to Ed asking when he'll have more PS kits. He usually has all the pieces, just has to put the kit together.

viperrwk

You could be facing a multitude of issues and U4 could just be a symptom.

I always fix power first - check rectifiers, VRs, change caps, redo HV section, connectors - because this can mask other problems and make you chase your tail. Reseating U4 is easy but if it still locks up you'll have to look elsewhere.

viperrwk

Did you ever figure out this problem? I just picked up a Jokerz! and have the same problem.

It started where it wouldn't boot at all, no matter how many power ups/reset buttons on MPU were done. Traced that to a broken ground wire on one of the coin microswitches that is in a daisy chain on the coin door. Resoldered that and it now will boot after I turn it on and off anywhere from 2-5 times, or turn it on and hit reset 2-5 times -- but usually does better with the coin door open (memory protect off).

Unfortunately my top display is totally dead, only the bottom one works, so I don't see any diagnostic messages. Is there any way to swap the two without desoldering?

Once booted it plays perfectly fine; minus a dead pop bumper and the dead double score square target; ran 4 hours, multiple games, no issues. Also can't seem to get into service mode either -- need to do more tracing on the coin door switches.