Well… it looks like I got myself into a right royal mess now with my attempts at diagnosing the problems with my Commodore 64. I know there’s some saying out there about having a little knowledge can be dangerous and this might apply to me here…

My plan was to spend some time over the weekend checking the voltage outputs on the motherboard with a multimeter to see if anything was broken. Thanks to some excellent service manuals you can find on the Internet there is a lot of useful information to help you achieve this. The great part is they go right down to testing the voltage across individual chips to verify which ones are faulty. However my own enthusiasm may have got the better of me.

Was excited to look into fixing this…

First thing I wanted to do was test the power supply to confirm that it was producing the appropriate voltage and current. I had previously tested it but wanted to do so again to also confirm that the new multimeter was working. During one of those tests though I may have accidentally tapped the wrong pins and ZAP the old power supply is no more. Bit frustrating as I was being very focused on measuring the correct pins and yet I still slipped up.

Without the power supply I can’t test the board so have set myself back substantially. Dumb move by me for not being careful enough and a hard lesson too for someone just starting out on this. I might be lucky and it’s just a fuse I can replace but still poor form. It means yet another delay on my path towards Commodore goodness.

My once working power supply (top)… now not so working.

So what’s next? I’ve got a couple of options right now. The first is to source another power supply  (if more than a fuse) and thankfully that isn’t too hard. There still seems to be enough of them out there that I might be able to get another one quickly. The other option is to see if I can find anyone locally who can fix both the machine and the newly popped power supply. It might be a more expensive option but hopefully it will be one that involves less of me poking things with a multimeter and zapping them.

Not quite as productive an update as I had hoped but certainly educational. Next time around I’ll hopefully be moving a little closer towards the working, gaming, etc and little less towards the spare parts bin. The only ZAP I ever want to see from now on would be related to Zzap!64…