21-CT-55 power supply failure

[Penthode]

Originally Posted by miniman82

Drive is excessive, but I can't figure out why. I can't even get the drive lines to go away with the control and the oscillator tube has incorrect grid voltage as well, not sure where to go with this.

Since we can assume the oscillator is on frequency, have you set up the synchroguide with the horizontal locking range as per the service info?

Is the horizontal waveform amplitude applied to the grid of the 6CB5 correct?
Have you replaced C232 (0.01ufd)?

Does the horizontal drive control work properly eg do you see a change in the picture?

Lin is fine, nothing amiss there.

Are you sure they are drive lines? (I am suspicious because drive lines = bad linearity and you said the linearity is okay). If you rotate the horz hold so the picture moves to the right, do the lines remain stationary (drive lines) or do they move opposite to the picture movement (retrace line image)?

Don't know, when Wayne was here we checked the HV and it was fine. If the shunt were set incorrectly, I would expect it to be much higher, or if it were red plating much lower.

I was wondering if the HV reserve is there. I guess if you are getting lots of drive, the HV is okay. But if the brightness is advanced, does the picture bloom or does the width increase? (This would indicate the regulator is dropping out of regulation and the HV being generated is insufficient).