An easy repair of a C64

Dirt and spilled capacitors

This Commdore 64C was in good condition for first sight, and worked besides some minor problems, like defective "0" key, and didn't have sound. Adding a spring from my donor C64 to the keyboard, for the missing "0" key was a 1 minute fix. However, opening up the case afterwards was surprising: this later C64C had a casing where there were no screws just plastic hooks to snap the keyboard in place, and snap the whole housing together. It seems to be a cheap solution, however was easy to open up for fixing.

Nice and clean, with new caps

Inspecting the motherboard, in general it was in good condition, however some spilling under two electrolytic capacitor grabbed my attention. Also, the fuse looked strange for me, it seemed to be home renewed: the hair thin burning wire run outside of the glass, and it was soldered to the fuses metal ends. WTF??

Soldered out the capacitors, and washed the main board to get rid of the remains of the fluid on it. Swapped the fuse from the donor, and soldered in the donor capacitors. Anyways, having the capacitors soldered out, I took the opportunity to measure it's properties. Turned out, that even the original capacitors were within specification, however the ESR values were 1.5, 2 times as high as the new ones.

Testing, testing...

Powering up the board, checked the voltages on SID, and I have found everything OK. The SID (the newer 8581 version) requires 0V (GND), +5V and +9 volt. I swapped with a known working one, for testing purposes. And let there be music, I said. And so, there was.

Hitech quick dry procedure

One thing left for the end, cleaning the bare casing thoroughly. All of those small black scratches, old dirt went away, and assembling together again when it dried out, we were ready to play a little bit. :)

Ready to have fun!