1950s or '60s vintage Zenith TVs, Need some info

[vortalexfan]

Originally Posted by DavGoodlin

If you find the caps are full-on open with very high ESR, I'm not sure they would reform. It the old days, I usually just bridged a new one across it to see if issue would go away. More importantly, if the cannot charge up to rated voltage using a high-impedance cap tester with an eye tube, just disconnect those sections and replace one cap as needed.

Often just the half-circle (usually the highest value) cap section is suspect as it gets the full DC supply initially before the tubes warm up and begin to draw current.

I usually find one out of four open, showing very high ESR, almost always on the lower values like 2, 5, 10, 20mf etc. Even if ESR is low, you may still find that cap becomes leaky at rated voltage. It probably went bad long ago but a good set like this Zenith might not show symptoms.

Well the Main Power Supply Filter Cap (which in these Zenith's, at least the ones I have) is just a single section can seemed to measure what I'm assuming to be either open or shorted as on my ESR tester (one of the small digital readout ones that you would get as a kit online either fully assembled or you would have to assemble yourself) was showing 29pF on the readout with no ESR reading or anything.

The sections that tested good had ESR readings of .77 ohms or less, (those were on the two 4 section cans) and the one 4 section can that had one bad section the bad section showed a lone 29pF readout on the display and no ESR readout, the one that had 2 sections bad also read 29pF and no ESR reading on the display, which like I said I'm assuming that means the sections are open or shorted.

The paper caps in the TV all read pretty close to spot on MFD value wise, but that doesn't mean anything, they could still be leakier than all get out.