I repaired this little Trinitron this weekend. KV-1204 from 1976. A friend of mine rescued this from the recycling, and gave it to me because it was dead. I replaced a few bad capacitors on the deflection board. The picture tube is really strong, which is unusual on these old Trinitrons.
Yeah! I pulled this off the shelf to get some pictures for Adrian's SOROC video, and figured I might as well fix it up while I had it on the workbench. You can see the "before" in Adrian's video at the beginning. It cleaned up pretty good I think!
Got it all working and reassembled. There was a cracked trace causing an address line to be connected to only two of the RAM chips, and nothing else. This was acting like an antenna and picking up noise.
Still missing a couple keytops (1, Z, and left Shift), but I found a couple I could substitute.
I can honestly say I've never seen a 2102 RAM chip behave like this before.
OK! I suppose it's time I migrated here - Twitter is kinda falling apart. I was @crtdude on Twitter for years - but someone already took that here.
I had a log of fun tweeting my projects and things I was working on, so hopefully I can regain that enjoyment over here.
