On Wed, Jul 5, 2017 at 2:23 PM, Francesco Messineo <email@example.com> wrote: > On Wed, Jul 5, 2017 at 8:03 PM, Ethan Dicks <firstname.lastname@example.org> wrote: >> Hi, All, >> >> I set up a retro-gaming event ... couple of VIC-20s >> ...the sound cut in and out... > > The audio signal is buffered with a single transistor > emitter-follower, so you would first check > it (solder joints and the 1uF electrolytic decoupling the DC after the > emitter-follower). Perfect. Thanks for the info. >> Another symptom is the colors weren't quite as "bold" as they were on >> the working VIC-20... > > Inside the VIC metal box there's a 10k potentiometer that sets the > video signal level. Again, this signal is then buffered by another > emitter-follower. A DC-blocking electrolytic is placed before the base > input to the emitter follower, so this one might also be dried out and > have high ESR. > Your best friend is an oscilloscope in both cases. Awesome advice. I'll keep your words in mind as I check the schematics. Thanks! -ethan Message was sent through the cbm-hackers mailing listReceived on 2017-07-05 20:00:03
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