[SOLVED] Really loud sound when turned on - ruled out power supply, hard drive, fans (video included)

[TyKim]

Video here: https://drive.google.com/file/d/11WUbT6DnrtldbRL3U8GB8ghucXBo8mWA/view?usp=sharing
Hey! I'm not a huge computer person so I'm sorry if this is a trivial question. Recently, my computer has started making this really loud, low pitched whirring noise whenever it starts up, without stopping. I've tried stopping the power supply fan and taking out the hard drive and it keeps going. I don't think it's the fans either just from using my ears, but I'm less confident with that. Either way, cleaning the fans didn't seem to help. Any help would be much appreciated. Thanks!

 

[Ralston18]

Use a long cardboard tube or rolled up piece of paper to use as a "hearing aid".

Put one end of the tube to your ear and carefully listen about and around the inside of the case to pinpoint the source of the whirring noise.

 

[Chris.Calvo]

Sounds like a bad fan bearing, not much would make a noise like that in a PC. Try what Ralston suggested.

 

[Sam4malaysia]

Thats funny. If it is not psu fan maybe cpu, gpu or casing fans. Trying stop each one of them using your finger or using a pen.