issues with fan on computer (noise)

[tremmor]

Wife has tower, quad core and noise. Everytime it starts
the fan whines very loud. its only noisy on start then settles down.
I blew out vents and inside of computer and hook back up and restart
and fan noise again. if i shut down and take the cover off tower on side
it doesn't do it. trying to verify which fan. I suspect its the fan on back of tower.
Im just trying to verify this is the one. Any other suggestions to verify?
thanks

 

[Troncoso]

If it only happens when the side panel is on, then unplug each fan and replace the panel, one at a time until the noise stops. That should tell you that the last fan you unplugged is the bad one.

 

[Darren]

When your system boots it starts all your fans at max power level until it boots fully. It's probably one of the fans plugged in to your motherboard, maybe even your CPU fan, as your fans plugged into your power supply are always on max power.

Unless the noise is causing a problem or persists past start up, I'd just leave it alone.

 

[beers]

Also, a lot of failing fans can be grindy on first start up if they've been sitting off for a bit, so it may be more time related than side panel related from a cold boot.