CanonMan

Arthur Edward Thomas. https://www.intergameonline.com/coin-op/news/arthur-thomas-awp-pioneer-passes

You've already opened a thread on this. No need for another one.

Pop the microswitch back in before you pull the holder out so there's less chance of it breaking.

Pull the switch/bulb holder out then unscrew the black collar.

I might have read it wrong, but you got nothing back because you told him not to send them back?

Have you tried replacing the electrolytic capacitors first?

Kynar wire?

A lot of newbies do exactly that. If that's not your style then welcome to the forum and enjoy your stay.

Yes, you need to contribute to this site, not just grab what what you want then disappear off into the sunset.

If the power supply turns out to be knackered I've got a couple of working ones going spare.

The M6376 chip on the ESP (sound/program) card sends a /BUSY signal from pin 1 which the M1 checks to see if a sample is still playing. Obviously this signal is missing because the chip is faulty or it's going through another chip somewhere which could be faulty. Try another ESP card and see if that cures it. If it doesn't, you need to trace the /BUSY signal back from pin 1 of the M6376 and see where it goes to. M6376_OKI.pdf

The spare blue connector could go to what appears to be two speakers either side of the cooling fan on the top of the back panel of the cabinet. It's a left-over from when the cabinet had a Video MPU board installed.

It can't be the correct one if Thesis was closed down in 1974 as Ron said

Ha ha. You'll never get that lot for £50, you piss-taker.

That's good news. Did you end up having to repair the MPU4 or was it okay in the end? Just out of interest, the triac drives are right next to the battery so it's not unknown for battery rot to cause payout solenoids to lock on and blow the 48v fuse. Just something to look out for....