Commodore 64 (C64) forums

Got a Plus 4 that wouldn't power up. Power supply was good, fuse was good. Seller assured me it worked before it was put in storage.
Probing the power connector revealed no difference in resistance between 5V and ground with the switch either on or off.
Measuring the resistance at the switch itself revealed that there was no contact made in the ON position.
Wiggling the switch's rocker would occasionally cause contact.
So I took the switch apart, indeed the contacts were oxidized or something like that.
Attached is a picture of the two contacts in there, one is cleaned with a pencil eraser, the other isn't.
See the difference?

Putting the switch back together is another story....

Meh, it was quicker than expected, since it turned out I still had a little tube of special contact grease just for switches.
The Plus 4 powers up. I haven't checked anything else yet.

Cool. The switch went together good then? Those switches are hard to find, these days, so disassembly and cleaning is a great option.
Nice Work!

I've gotten good at switch surgery because I also do the same on my 1960s Tektronix lab stuff. There are some very nice switches in there that are just beautiful pieces of engineering. But either impossible to find or you get the right one but with the wrong color lens for the illuminated ones.