Please help fixing PSU Tagan TG480-U22

Discussion in 'General Electronics Chat' started by Bill S, Jan 31, 2015.

  1. Bill S

    Thread Starter New Member

    Jan 31, 2015
    Please help me fixing a Power Supply Unit.

    The power supply is the Tagan TG480-U22 and was shorted, it was tripping a circuit breaker on house fuse box, when Computer was OFF (Power On switch not pressed) and PSU switch ON. Two identical mosfets have been replaced inside the PSU, on the board that is probably called "Active PFC". Plaqued capacitors have been replaced, too.
    On the video, the PSU is connected in series with an incandescent lamp 40 watt 230V, and the whole circuit is pluged in to 230 volt AC socket . The multimeter (which can not measure square waves, ie around 230 volt square wave shows 168 volt on multimeter) here shows around 70 volt onbthe lamp. I assume that the pulses are square wave to the lamp, I do not know it for sure.
    The power supply specifications are: operating voltage 95 - 250 volt ac. The PSU cable +5VSB measures 5.13 volt DC when I connect the 230V socket (video), which I think is good news.
    - Is this (PSU + Lamp) circuit behavior normal if the PSU is functioning OK ?
    - Should I connect the PSU to 230V (and command it to power on, by grounding green wire) ?

    There is a video, that I've recorded. You can see it here:

    Thank you