Sunday, August 8, 2010

AT PSU issues

yep the AT PSU i bought in calgary has issues, has soon as i put a load on it, it shuts off, and all i used for a load was just a 60mm 12v fan, from a computer.  the shop i bought it from said he was not sure if it was in working order, but he will try to get me another working one if this one did not work.


  1. Have you put a load on the 5V rail? If you don't it can't give 12V without the 5V rail going over voltage, so it will either give a low 12V or shutdown. There is only one regulator for all the voltages inside a cheap PC PSU.

  2. Yup seconded,SMPSU's have a minimum load below which funny things happen. I use a low value power resistor tie wrapped onto a piece of aluminum sheet as a dummy load.

    Your fan being an inductive load and not on the power rail that drives the regulation will have made the situation worse.