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Wow! More great info! Anyway, the hum is not tuner adjustable, but is present at all times and is volume controllable.The power tranny is on the opposite end of the chassis, so I don't think that the magnetic field theory will help this time. When I get time I am going to check that video detector diode. Again, the coil that is in series with the diode is open, so we know that there going to be some issue there, just not exactly what so far. I don't think that the video section is going to produce the hum and certainly not the lack of vertical sweep. Bear in mind that this set has been re-capped and was the same before the work as it is now, so that at least should eliminate capacitor issues (with the exception of ceramic discs) and botched work on the re-cap.
I am almost ashamed that I am soon to graduate an electronics degree program, but honestly, they certainly don't teach much of anything in tube type or consumer electronics of any kind. In my last semester (next), they actually have a troubleshooting class which involves signal tracing with a scope, but of course we will be troubleshooting old broken solid state signal generators. I am so sick of turning on LEDs or incandescent bulbs with SCRs, OP Amps, NPN transistors, and relays! There is so much more to electronics! I did get to build a circuit on a self made (from scratch) PC board that is capable of displaying indication of outputs and controlling a stepper motor through a P-basic computer application. I just hope that I will know enough to be a capable electronics tech upon graduation. My GPA is 4.0., but great grades don't change the program. Essentially they are trying to teach you what it takes to land a job which ends up being knowledge of various configurations of induction motors, starters, controllers, PLC programming, etc.., with a foundation in relatively simple series and parallel circuit design and understanding through Ohms law.
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