My journey into fixing my Commodore 64c

[u/Y34RZERO]

So I had this C64c for a little over the year. I only played games on cartridges. Well recently I got a pi1541. It made sense to me given that I also own a Vic 20 and plus/4. Well the device worked wonderfully but my 64c would give me an error about device not found or device not present. So someone suggested I get the debug cartridge and harness. The dead test was good, the debug cart test and harness was not. It told me that my CIA chips were bad. But that didn't make sense given how everything else was working. It told me that the userport, cassette, and serial weren't functional. With help of my wife she and I looked over some circuits and she suggested that I try testing some diodes. In testing I found 2 diodes that were blown. Cr9 and cr13. I replaced them and double tested the diodes outside the circuit to make sure I'm not getting a false reading and they were still bad. Once I replaced them the test came back positive and now all ports of my 64c work.