Simple testing of a PSU - no lights, no fan

archiet

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Nov 21, 2009
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18,510
Hi guys, I'm a first time system builder and I'm stumped on my first problem.

I purchased an i5 bare-bones kit from newegg which includes a Raidmax RX-730SS 730W PSU. The packaging that it came in looks good and the PSU looks good. So I mounted the PSU in the case without any problems. As a first test, without anything connected, I plugged it in to a wall outlet and then turned it on. I heard a faint vibration but it's hard to tell what I'm actually hearing. This PSU comes with a fan and blue LED light but nothing came on when I flip the switch. I didn't see special switches for just the fan or the LED but I'm not sure if they should light up without plugging anything else in. I confirmed that the PSU is set for 115 volts.

Any thoughts? Is this PSU bad?
 

ulysses35

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make sure you plut something into a molex connector - ideally something low vlaue like a fan.

This will tell you if the PSU is still live - however it is a little more complex as a PSU may power up some components but might be putting out low volts / amps causing your PC not to boot. If this is the case, then eventually the PSU will fail completely
 
So far, your PSU is acting normally. The only thing that should happen with the PSU switch on is that the small, 5 volt standby power suppy inside comes on. And that will give you no visible indications, until your motherboard is plugged in. Then the little red (usually) motherboard power LED should come on.

Look in your motherboard book. One of the wires is labeled something like 5V STANDBY. That should always be present when the PSU is plugged into the wall and the PSU is physically turned on.
 

archiet

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Nov 21, 2009
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18,510


Thanks for pointing me in the right direction and thanks to the comments by others as well.

I used a cheap PSU tester that naturally connects the "power-on" pin to ground and the fan turned on and the blue LED lit up. I also connected a molex connector to an auxiliary fan to test it and everything seems fine so far.

BTW, the PSU tester burned out after using it twice today.

Until I get a wrist grounding strap I won't be going near the motherboard or the CPU.

Thanks for helping out a beginner.