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Old 06-07-2012, 10:19 PM
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JamesDean JamesDean is offline
Electrical Engineer
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,016

That board looks like most of the ones I've worked on. I would be sure to touch up the solder points that you think look suspect.

The transistors are supposed to dissipate a maximum of 25W at full power, however these guys are operating at maybe 5-8% of maximum so I doubt they dissipate too much heat.

Yes the varnish remover easily removes the coating. I only apply it to the rear of the board when I do work on these as there no real need to remove it from the other side. The capacitors, once de-soldered, come out with minimal effort of the pliers.

Hope this helps! If you've got any other questions post up!

Originally Posted by brewtoo View Post
I have a couple of questions, JamesDean. About to replace caps in one of these. See photos below, please. In one corner on the back of the board, there is some really sloppy soldering. This box had never been opened before. Have you seen anything like that? Seems like all that shellac goo they put on there would insulate the heat sinks on those transistors, preventing the heat sinks from dissipating heat? All my components are pretty well glued down to the front of the board. Does that paint remover of yours work pretty well getting the goo off? Thanks!

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