Why does recapped PSU leak to ground?

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  • ic32
    New Member
    • Nov 2006
    • 1

    #1

    Why does recapped PSU leak to ground?

    I recapped the Antec TruePower from my Antec Sonata case not long ago, and I now get what seems to be leakage current of about .05V even when the PSU is turned off with the switch on the PSU case. I will double check all these facts when I get home, but I think that it also leaks the same amount for at least several minutes when unplugged from the wall. Since I never thought to check this before, I don't know whether this is normal. I can't remember whether this is from the 5V or 12V line to ground (either case or straight to wall ground, which I have personally newly wired and verified all the way into the ground beneath the house)

    A summary of my recap: I replaced all but three capacitors with Panasonic and Nichicon caps from Mouser. I also desoldered a number of wires from the harness so that I could remove unused Molex connectors and make the PC and PCU cases easier to cool/maintain. I did not replace the two large AC filter caps for lack of better replacements. I did not ultimately replace the single non-polarized capacitor—I didn't have one handy. My first power-up resulted in the blowout of one of the smaller capacitors (don't have the specs on hand). This prompted me to conduct another very careful reexamination of things, during which I found that I had replaced the non-polarized capacitor with something polarized, though this was not the cap which blew. I'm fairly sure that I didn't reverse the polarity of the blown capacitor, but I figure that could be the result of either the use of a polarized cap instead of non-polarized, or that the desoldering of a small capacitor with a RadioShack desoldering iron/pump combo and then reuse once I realized I had no comparable part.

    All voltages seem to be very stable at all Molex connectors, the machine has run for several weeks of 24x7 uptime and frequent recording of analog and over-the-air high definition TV. I haven't rushed to do some Prime95 burn-in testing, in part because I wondered whether this apparent leakage current was explainable.
  • Per Hansson
    Super Moderator
    • Jul 2005
    • 5895
    • Sweden

    #2
    Re: Why does recapped PSU leak to ground?

    The main caps discharges to ground for safety reasons

    That's the way I think it works anyway (so you can open up the PSU without being killed by those 400v caps...)
    "The one who says it cannot be done should never interrupt the one who is doing it."

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