Working on C 128 PSU

[motrucker]

I received my new power supply and tested it. I was able to get 5.21v DC on pins 1 and 4 but got 2.6v AC on pins 3 and 5. This totally puzzled me until I removed the 1.6a fuse and found that it was blown. I guess I expected a blown fuse to not show any reading because that was what I experienced when the 4a fuse was blown. Anyway, I replaced this fuse and now everything works.

 

Thanks to everyone for their help. I'm going to continue learning about the innards of the C 128.

Good to hear you got this problem sorted out. The C-128 is, by far, my favorite 8 bit computer.

You might to look into adding the 64Kb VDC upgrade, and using a good size REU. These will expand what the 128 can do.