@chris b managed to sort out a multiball/ lock problem on a whirlwind (very similar game to ES) that had defied a number of knowledgeable amateur and professional folk on the scene
Maybe take it to him if he has capacity at the moment ?
Or could you take it to nlp? See if folk might take a look ? You will have the best brains in the uk pinball scene in one płace ?
It can take "game conditions" to yield a problem. Playing with switches individually in test might not do it, as it is only their interaction that prompts the symptoms. - the "squares" on the switch matrix like
@ronsplooter had with his space station shop log
My whirly was spitting two balls into the shooter lane, but only when the first ball was locked. And only periodically. The ball trough switch for the second ball was sometimes sticking. Might you have a sticking microswitch, one that takes a second to reset, as I did ?
Do a rigorous switch test where you activate multiple switches simultaneously to see whether you can find a phantom. One iffy diode/ wrongly wired switch combined with another switch being closed (ie ball lock) and a third switch being operated can cause all manner of chaos. Obviously focus on those that are relevant to the problem you are having
Is the shaker triggering a particular "hair trigger" switch or opto ? Put it in switch test with balls in relevant pisitions and shake the crap out of the game to see if one triggers
Next test for me would be to swap boards for known working ones - get an interconnect from somewhere, or get your game alongside a working system 11 and beg the owner to let you swap boards over. I diagnosed sound problems on my banzai run by taking the board from my old
bk2k.
I can only then suggest things like ...... power supply, are you getting ac ripple on the 5v ? Cleaning connectors? Reflowing the pins.