Can I test my power supply just plugging into an outlet

Edward77

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Nov 18, 2010
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Hello, I just got a 500 watt power supply and thought I would just plug it into the wall outlet but the fan did not come on. My question is shouldn't it come on? I wanted to see if it worked before installing in the PC.
Alby
 
Use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.