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repairing ATX power supply...?

Discussion in 'General Electronics Chat' started by takao21203, May 10, 2012.

  1. takao21203

    Thread Starter AAC Fanatic!

    Apr 28, 2012
    I used ATX supply for electronic converter to generate higher voltage.
    Eventually I patched the converter, and reached a limit, the diode + MOSFET both latched.

    I was able to put the converter back to working condition, however, the ATX supply also no longer works.

    It still emits this typical clicking noise after switching it off, so I guess the high voltage side is still intact (controller IC).

    I measured the diodes on the secondary side, there are two double TO220 diodes, both measure short (0 OHms), and two double diode (round case), which measure 180mV forward voltage.

    Would you say it is worth unscrewing the PCB, remove the cooler grid + diodes, and install new ones?

    I am not very experienced with these circuits, but have some experience.

    This also is not about the high-voltage side of the circuit.

    I can show a picture if this helps.

    I picked up this supply a year ago from junk, never used it until recently for the voltage converter. Isn't very powerful at the 12V side, all it can crank out is about 3.6 Amps (routed through the dc/dc converter).

    So, before putting in 5 hours of labour I should rather invest in a new one, or electronic transformer?

    I would take it apart anyway in this case to get hands on the components, and because these circuits are interesting for me. If I can repair it with little effort, good.
  2. SgtWookie


    Jul 17, 2007
    I'm in the States, and have no idea what ATX power supplies might cost where you are.
    Over here, one can pick up a used/junked ATX supply for little-to-nothing.

    You have to realize that your time is worth something, and how much sense does it make to buy parts to put into a "free" device? It really only makes sense if you are doing it for a learning exercise; but you'll learn just about as much by simply finding all of the parts that broke. It's not a total loss; you can always salvage components that are still good; for example the toroids, E-core(s) and magnet wire.
  3. takao21203

    Thread Starter AAC Fanatic!

    Apr 28, 2012
    About $40 for the cheaper one's, local store.

    Actually I have replaced the two TO220 double diodes today with a DPAK diodes assembly. I hope for the best that the rest of the board survived.