Is it appropriate to request help for fixing a Hook machine in this forum? Sorry, but I'm new, and if I should post somewhere else, please let me know.

I've had a Hook pin for about 10 years now. Recently, the "Left VUK" stopped working - if a ball gets caught in there, it doesn't shoot it out. The machine tells me what switch it is, and I've found the switch underneath it, but I don't know how to test it. I'm not experienced at this, but am fairly handy. (I've replaced the flipper coils already)

Can someone walk me through how to test this switch to validate it's bad (eg: with my multimeter), and suggest where to get another one? I'm trying to get this playable again in time for my son's birthday party.

Thanks!
David.

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Anyone have any clue what could be going on here?

Thanks very much for the input. It's the whole "investigate what's going on" part where I'm stuck, unfortunately.

I've got the tools (multimeter, soldering iron, etc) but am not very skilled in using them. Are there any helpful beginner guides on how to determine where to stick my multimeter leads, and what results to look for?

@kba78 is there a way to test for that?

I tested all four bridge rectifiers with the method detailed here:

and all tested out good.

I noticed after turning the machine on that the PIA and +5v lights come on and stay on, and the blank light never comes on. According to the manual, if the PIA light stays on, then there's a problem with "one of thee 6821 PIAs" but I don't know what those are. I suppose I'll do some more googling.

I also tested the 3 test points on the power supply board. The +5v tested at 4.1v. The +12v tested at 11.1. The -12v tested at -13.5.