The More Fun Fixing It channel returns with its C64 repair finale, closing out a five-part adventure of troubleshooting vintage Commodore hardware. Host Lee admits that his recent repair streak has been less than stellar, so this time he calls in expert reinforcements: Adrian Black from Adrian’s Digital Basement and The Retro Channel.
Their mission begins with a suspicious C64 showing a black screen and inconsistent behavior. Lee’s initial diagnosis points to the PLA chip, but after swapping ROMs and checking voltages, uncertainty grows. To make matters worse, intermittent crashes and psychedelic display glitches suggest multiple faults at play.
Adrian’s Analysis
Adrian joins remotely to review the test results. His verdict? A failing BASIC ROM, with checksum data revealing corruption. He also suspects that bus conflicts or voltage inconsistencies might be behind the chaos. Lee follows his advice, swapping ROMs and probing signals—but the system remains erratic.
Then Mark steps in with a fresh theory. He suggests testing the PLA’s I/O line, specifically pin 12, which controls the VIC, SID, and CIAs. His reasoning proves spot-on: the signal measures far below expected voltage. The culprit is confirmed—the PLA chip.
A Collaborative Fix
With the faulty PLA replaced, the C64 springs to life. The repair wraps up the C64 repair finale on a high note, showing that collaboration and shared knowledge still reign supreme in retro computing. Lee thanks both Adrian and Mark for their sharp insights before teasing his next challenge: a lineup of rare Silver Label C64s waiting for their turn on the bench.
