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Get rid of one problem, another pops up. Looks like I have a bad 2N2907 transistor on my C4S board. Appears to be a physical problem, I can tap the transistor case and cause one one of the LEDs (3rd from power)to go out; the adjacent one brightens up. Earlier, I got it working, but had only 64 vdc on the third (bad) lead, all others were in the 77vdc range. After tapping the unit, the LED went out, the other half shot up to 100 vdc or so. (when I get it working, it lasts about 5 minutes after power-up then "pops" and the LED goes out, believe its an internal thermal issue)This is NOT a bad solder joint on the PCB, I visually inspected with a 10X lupe and the joint looked good. I re-soldered anyway, but the same thing happens, once it is warmed up, physically tapping the transistor with a wood stick causes the problem to disappear / reappear. I removed the C4S board and restored the circuit, the unit works fine. BTW, I chose the name "Solder Slinger" because I spent years wiring and soldering telephone circuits, then got into modifying Dynaco and other tube gear, I was careful soldering the transistor, did one lead at a time then came back a couple of minutes later to do the next lead didn't want to overheat the transistor (and have a temperature controlled iron).
Any suggestions other than replacing the 2N2907?
Thanks,
Ed
Edits: 03/03/08Follow Ups:
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