21-CT-55 power supply failure

[miniman82]

I decided to bypass the IF for the time being, injecting video into the 1st vid amp and disconnecting power to the IF strip. Found something odd: the bandpass amp grid is registering 0 volts, when it should be -15 or so. I can't figure out why it's not biased right, all the resistors in the circuit measure correctly and the caps are new. With the grid at 0, that tube would draw more current that it's supposed to which might explain the power supply drain. It might also explain the dot crawl I'm getting now.

[miniman82]

For continuity, this problem was finally fixed here: http://videokarma.org/showthread.php?t=252849


The voltages on the bandpass tube ended up being a Sams typo, the CT-100 chassis had the same readings. After fixing the problems detailed in the thread above, dot crawl is much better as well. I can probably make it disappear by tweaking the 3.58 trap in the luma line. So glad this is finally over.