PL 3300 Series II rebuild/upgrade

scottonnob

Journeyman
Joined
Apr 28, 2015
Messages
251
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Well, I don't know if I solved the mystery, but I found something. First, I took the pot back out and completely disassembled the unit. As one of you predicted, it was clean and fine. However, the two 1000uf 50v caps that sit behind the pot were loose. I noticed this the first time I went in there to work on the pot. But the solder joints were fine, so I just re-flowed the joints and pushed the caps down against the board to address the looseness. Today, however, when pulling the pot out again, I decided to pull those two caps, as they were still not as solid as I would expect. When I pulled them, I checked for continuity. One read consistently fine. The other, however, was showing only intermittent continuity, until it finally lost all connection after I adjusted the leads. Afterward, even while fiddling with the leads, the continuity never came back. I'm wondering if there was damage to the caps, new Nichicon Muses, that was either the way they were delivered or occurred during installation, which I highly, highly doubt. But the way the continuity on the one cap went away after I jiggled it a little more makes me wonder if the same thing occurred as it heated up in circuit and the crappy connection finally broke. I don't even know if such a thing could cause the hum I was getting, but I ordered two new ones, and we'll find out when I put it all back together.
 
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