A Commodore 64 can look completely lifeless even when its power rails and clock circuitry are healthy. In a new repair session published 17 October 2026, Adrian Black of Adrian’s Digital Basement works through three faulty Commodore 8-bit computers, beginning with an unusually early C64 assembled from apparently mismatched case parts.
That first machine produced no video signal. Adrian measured the expected supplies and clock inputs at its VIC-II, but found no output at the chip’s video pin. Swapping the unmarked VIC-II brought back the startup screen. He then paralleled a resistor at R10 to brighten the early board’s dark picture and ran a RAM test. The machine was not completely finished: its keyboard still needed service, and its SID sounded marginal during music playback.
The useful lesson is the order of diagnosis. A blank display does not by itself implicate the CPU or ROM; confirming whether the video chip has power, clock and an output narrows the fault substantially. Adrian is careful about the machine’s provenance too: the low-numbered case bottom does not prove that its Rev C board or later-looking top originally belonged with it.
For builders and repairers looking for period parts, Anders Nielsen’s retro IC collection at iMania is related reading; this repair illustrates why identifying the exact chip and board revision matters before choosing a replacement.
Watch the full, roughly one-hour video: “Mini Commodore repair-a-thon: Strange things and a little carnage” by Adrian’s Digital Basement.
