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Originally Posted by IsthmusTV
I actually did some work on mine this weekend. I've had a nagging intermittent on the video output board that caused the luminance level to go way high. I was sure that it was the socket of the 12BY7, so I replaced it. That was not easy because the board is pretty well cooked so I had lots of problems with lifting traces, etc. And of course, that didn't solve the problem  I took another stab at it yesterday, and under magnification, I found a bad solder joint on one end of a resistor that had gone previously undetected (I'd been over this board countless times). I still have a minor intermittent hue shift that I need to track down, but otherwise it's playing great. Long live Abingtons! |
So funny... because one thing I've not mentioned yet is that the set started developing intermittent bright luminance. tapping/rocking the 12BY7 would cause the problem to get worse, so pulled the chassis. The board was pretty nuked underneath from the heat; someone had bridged several bad board traces with fine wire and slider and did a fairly decent job.
That resistor... the same one you mentioned- looked like the leg was oxidized and solder never flowed onto it properly but it took a while to find. Problem solved.
I put a socket saver between the tube and socket to keep the board from cooking any more.
Also, the horizontal instability was a dirty tuner tube socket. It was the only one that, when rocked, would have an effect on anything. It's solid for now!
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Originally Posted by BigDavesTV
Well, I made a start on my CTC-7 Sanford chassis, yesterday! I have the older version that has the 5U4's mounted atop the power transformer. Over the years, the heat had dried out the wiring insulation between the tube sockets, and years ago some technician had spliced in some wires and I guess they worked, but looked absolutely awful. I have replaced them to tidy things up. More to do, but already I feel better! :-)
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Good good! Keep us informed.
