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Old 12-17-2015, 02:45 PM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by Kamakiri View Post
Voltage test didn't change with all 4 tubes removed, so I went on to this. The meter stopped at almost exactly 6.8 K Ohms.
Well, 6.8K is reasonable enough, considering that the B+ bleeder string to ground (R127A and R128A) add up to 8.1K. Current will only be around 45 ma., nowhere near the 175 or so ma. that's going thru poor R127B.

It almost looks like a B+ filter cap is breaking down under voltage, like maybe a cap has been replaced with one having too low a voltage rating. The most likely suspect would be C4A, which should be 40 mf and rated at 450V. Does the C4 can show evidence of heating?

Last edited by old_coot88; 12-17-2015 at 02:54 PM.
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