RCA 621ts Restoration

[old_coot88]

Originally Posted by vts1134

One last thought.
If the problem is coming from the video section would it still manifest itself with no video signal present?

Yes it would, assuming the raster has still got that heavy white bar in it. That bar's still present, right? If it is, there's another trick you could use that doesn't involve lifting any connections or injecting a signal (the bar is the "signal"). Get that trusty .1mf cap again* and hook one end to ground, and the other end to a clip lead. Starting with G1 of the CRT (this set injects video via the grid instead of the cathode), and connect the cap to it. This shorts the signal and should produce a blank or near-blank raster. Then take the clip lead and progressively work back, shorting the plate of the 2nd video stage, then the grid, then the plate of the 1st video, then the grid, and on back through to the plate of the 6H6 and then the cathode. If at any point the bar remains unaffected, you'll know it's originating in the stage you just left, 'downstream' of the shorting cap.

Be sure and discharge the cap to ground after taking it off the plate of a tube!
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*If the single cap is not killing the bar sufficiently, and if you have more than one of those .1 caps, put as many as you can in parallel to get higher capacitance for better shorting effect.