i have a gateway profile 6 series computer thought mother board was bad. replace mother board but it will not power up. red light on mot board will blink when you plug in power cord. the fan on the power supply will not run.
Welcome to Tom's Hardware Forums,
If you have a multimeter, the easiest way to test the PSU is by jumping the green and black wires on the 24 pin connector. That fools the PSU into thinking it's hooked up to a motherboard. Once the PSU is jumped (and can produce power) check the pins with a multimeter. Voltages should be close to the specified voltage for that pin. This link shows the pinout and corresponding voltages http://www.playtool.com/pages/psuconnectors/connectors.... and this shpows how to jump the green and black pins with a paperclip http://seasonicusa.com/RMABeta/JumpStart/JS.pdf (direct PDF link)
Hope it helps