21-CT-55 power supply failure

[miniman82]

Originally Posted by Penthode

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?

Yep, everything is set up right and I have equal peaks on the wave coil.

Is the horizontal waveform amplitude applied to the grid of the 6CB5 correct?

Yes, but the waveform has a flat top.

Have you replaced C232 (0.01ufd)?

First thing I did.

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

It works, but because the oscillator is making such a large waveform it doesn't get rid of the drive lines.

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)?

The line moves opposite of the picture. That means it's not a drive thing?

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).

No blooming, seems to have plenty of brightness. BTW, Wayne is probably right about the picture. It seems to be noise, not hum or anything else.