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My week for bad caps...

M

Mark Zacharias

Jan 1, 1970
0
McIntosh MC30: bad coupling cap driving grid bias positive, bad multi
section cap open / leaky.

McIntosh 225: bad multi section cap and voltage doubler caps.

(I had worked on exactly 2 Mac tube units in about the prior 10 years. Had 2
in one week, and took in a 275 Gordon Gow Commemorative model yesterday.)

Carver MXR-130: bad 220 at 10v loading the 5 volt supply for digital
circuits; shorted 100 at 10v causing a muted audio condition in radio
section.

Marantz NR1501: shorted low frequency rolloff capacitor on surround right
channel.

Tektronix 465: (eBay purchase "as-is") Open 5500uF C1542 in main power
supply 15v source. Replaced it, now had functions work but still had
blanking related problem. Actually could not turn intensity down enough to
blank. Shorted 1uF at 150 volt cap in CRT bias circuit. Tek scopes can be a
little scary, but got a good working 465 with video sync option for 85.00...



Strange happenings...


Mark Z.
 
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