> On 2021-09-02, at 14:08, Francesco Messineo <francesco.messineo_at_gmail.com> wrote: > >> Besides VIC itself? The ROMs and if they are present, the 65245 bus >> buffers. The latter can be replaced by 74LS245. >> >> But I also had bad RAM, a bad LM323 voltage regulator and a bad 74LS138. > > I can add also (from real repairs): 6502 (very rarely, but happens), > the 7402 on the clock generator, a 6522 jamming the databus. >> >> So dust off your scope and go hunting. > > that's the only good way. Sure. It's just that during my running the workshop time we practically had no VC-20s here. I barely recall repairing maybe two or three (don't remember now exactly but only a less than a handful for sure) over almost eleven years. Therefore I have no "feel" of what typical failures in those machines are. Shall find out eventually but starting at the most probable place statistically helps saving time. Thanks guys - off to vacuum cleaner ;-) -- SD!Received on 2021-09-02 15:00:21
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