Re: Antec Earthwatts EA-500 500w PSU

I just had to open up my EA-500 because the fan wasn't spinning. I don't think the power supply was overheating, but I was pretty sure the fan used to spin all the time. I guess some intermittent fault happened in the transistor or its solder joints because it runs so hot. I replaced the transistor with a 2N3053, which is in a metal can case that can dissipate heat better. Now, a few comments about the circuit.

The fan is obviously supposed to spin all the time. The 390 ohm and 150 ohm resistors connected to the transistor base...

Re: Big caps failing, but small ones seem ok

I ended up building a simple ESR tester, using a 555 to drive step-down ferrite core transformer, and observing the output waveform using my oscilloscope. I had some difficulty with test lead inductance, but after some changes I got it to work well enough that I could test the small caps in circuit. It seems they're all good. Almost all of the large caps with gold/brown lettering are obviously bad, even including most of the ones that aren't bulging. Here's my [URL="http://dreamlayers.blogspot.com/2011/08/bad-capacitors-and-esr-testing.html"]blog...

I would like to fix a 10 year old Soltek SL-65KVB motherboard because it has a P3-1000 and an ISA slot, making it a nice way to use some old hardware. It has a lot of GSC electrolytic capacitors.

Over a third of the 6.3v 1000uF and 1500uF capacitors with gold/brown lettering are at least bulging. I obviously have to replace all of those.

There are 27 or so smaller GSC electrolytic caps with silver/white lettering. Two are 470uF and the rest are 100uF or less. None of those show any obvious physical signs of failure. Do I have to replace all of those too?
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