PSU fan (power supply fan) not spinning. But computer works

fanoverheatingpower supply

The PSU fan on my computer is not spinning at all. I've now run a high def video for 20 mins and it's still not spinning at all. I read there's power saving features that will power down the fan, but I'm really suspicious. (Read details below.)


  1. Is this normal behavior?

  2. If the fan may be optimizing for power usage, how I can test the fan? Ideally, without pulling it out of the case.


  • PSU Model: LSP Ultra 550W ATX Power Supply
  • All temperatures are normal or low according to SpeedFan. (CPU, HD0, Core, and other temperature monitors.) But I wonder if this detects the heat of the PSU itself.
  • I'm having trouble with a video card. The card might be busted. When removed (and using built-in video) the computer works fine. But sometimes that's a sign of a power issue. When the card is in, it won't display video but Windows seems to load. Video card worked fine 1 week ago, but then I physically moved the system. Could have been damaged in transport.

Best Answer

If your temps are fine, then you're fine. If the fan turns on for second or two on boot and/or shutdown, then it's fine and it will only need to turn on when enough power is being used for it to need some cooling. Mines never turns on other than when it boots/shuts down which is just a way of checking that it works because it doesn't ever reach past 20% of its need total power capacity (which it only turns on when it's around 40% and up)

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