PC power supply tester

A failure of PC power on is most likely due to the defective power supply or motherboard. i would first troubleshoot the power supply. 3 usual methods are

1. Replace by another working power supply.
2. Short green and black wires to see if the power supply gets power on. It is better to have a suitable load connected in case zero-loading damage.
3. Test the power supply by a tester.

i pick method 3 and recently bought a Antec Digital PSU Power Tester, which can easily check the health of PC power supply.

1. Plug 20/24-pin and 4/6/8-pin connector to the tester.
2. Turn on the power supply, the tester will display the voltage level and PG (Power Good Delay) value. If the voltage/value is out of normal range, a beep alarm will sound.
   

   Voltage      Normal Range
   ============================
   +5V         +4.75V to +5.25V
   -12V        -11V to -13V
   +12V1       +11V to +13V
   +12V2       +11V to +13V
   +3.3V       +3.14V to +3.47V
   +5VSB       +4.75V to +5.25V
   PG          100ms to 500ms
   

3. Plug one of SATA/Molex/Floppy connectors (not the same time), the LEDs will light up if no problem.