Bottlehead Forum
General Category => General Discussion => Topic started by: aragorn723 on July 28, 2017, 03:27:04 PM
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Anyone know how to test a capacitor with 4 leads? It is the power supply capacitor in a integrated amplifier (soldered to a board). Thanks,
Dave
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that's probably two capacitors in one package. test each one separately.
Michael
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Funny thing about the cap though, is that is looks like 2 of the leads aren't connected. Only 2 of the leads have traces going to them.. The solder joints for the caps are the diamond shaped patterns in the attached picture. Oddly enough the other 2 are soldered also :P Does that make sense?
Dave
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Yes it does, the extra leads are just attachment points for a stronger mounting. If look closely at the label they are probably marked in some way...John
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Gotcha. Should I go ahead and de-solder one of these monster caps to test it, or would it be better to check some of the voltages first? I suspect one of these 3300 uf caps blew (part of the power supply) but don't have anything to back that up yet, except a toasted resistor after the driver stage of the circuit.
Dave
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That style of cap hasn't been around for very long, what leads you to believe that it's a problem?
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There's a smoked resistor after the driver stage, which suggests an overcurrent situation. Also, there is no sound. I could just swap out the resistor, but something upstream caused the issue, and right now that cap is the only thing I can think of. Am I missing something?
Dave
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Here's a quick update to the amp situation. Turns out that resistor is ok. According to the schematic, it is supposed to be 470 ohms, and measures at 469 ohms. I thought for sure that would be toast?? Looks like it's time to check some voltages.
Dave