Quote:
Originally Posted by Chris K
I think what I’ll do Kevin is post a list of the caps I’ve replaced and a bigger section of the schematic. I’d like to know for education purposes what’s causing this specifically and how I can diagnose issues like this in the future instead of doing a bulk recap in the power and deflection sections. I’d like to be able to say oh that’s what caused it and not well I changed everything and that took care of it.
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You can do that but you'll be spending a lot more time getting things corrected. Right now you know the grid of the horizontal output tube is under biased, and it's pulling more plate current than intended. Besides paper caps it's possible the 560pf mica grid coupling cap is leaking positive voltage from the horz oscillator onto the horz output grid. You could try pulling the 6BG6 and see there's any residual voltage remaining on pin 5 of it's socket. Speculating we can assume the higher than normal plate current the 6BG6 is drawing could be pulling a B+ down few volts. That happens because these old sets don't have much if any voltage regulation. And the horz out is probably the biggest consumption of power.