In his latest video, Jan Beta tackles a Commodore 64 board repair that, at first glance, looks like a lost cause. Sent by fellow retro computing YouTuber Wulfgang (from Retro is the New Black), the 250407 board arrived with key chips missing, signs of previous rework, and some physical damage. Still, Jan’s curiosity (and stubborn optimism) won out. He rolled up his sleeves to see if this could be anything more than a donor board.
The board was missing essentials like the SID, VIC-II, PLA, CPU, kernel ROM, and a 7406 logic chip. It also had a non-standard power switch, several damaged capacitors, and a rough-looking desoldering job around the ROM area. Jan started with a full visual inspection and basic continuity checks, then moved on to replacing visibly broken components. He also patched several broken traces using magnet wire—particularly in the heavily abused ROM area.
With voltage levels confirmed and power flowing correctly, Jan inserted known-good chips from his collection. A Dead Test cartridge revealed a blank screen—followed by confirmation of RAM faults. Rather than guessing, he used the DesTestMAX tool to identify specific failed RAM chips tied to faulty data bits. The verdict? Four bad chips.
After desoldering and socketing all four RAM ICs, Jan tested again—and it worked. Bit errors were gone, RAM passed, and with a salvaged ROM installed, the board booted cleanly into BASIC. Only the missing SID kept the diagnostics from reporting a fully healthy machine.
What started as a potential parts board is now fully functional (minus audio). Jan’s video walks through each stage with clarity and practical Commodore 64 board repair tips—ideal for anyone dealing with similar C64 issues or just curious about the process.
