[SOLVED] Random flapping noise on new computer is driving me crazy

Solution
I'm a bit scared to stick a pencil in the fan blade while the computer is running to be honest, might it not damage the fan?
No it won't, fans does not spin fast enough plus they're made of plastic. You can do it with you're finger if you're no kid (just kidding don't take it badly please 😋) it surprises more than it hurts. I do it with the index but you can use your thumb it's more robust you won't feel it, promise 😃 Archaic59 is right though you have to stop them one at a time and see if the vibration goes away. To my ear it looks like a cable in fan blade's path or worse yet, a dying fan. Tend to think it's coming out a fan. Also don't forget to try the power supply fan and graphic card fans as well, one of them is the culprit.
Just received my new machine and it's making a very subtle yet quite annoying flapping noise on a random basis. Here's the noise: https://vocaroo.com/cxNIAXUU5Ou

I have 2 case fans and one CPU fan: View: https://i.imgur.com/sxHiNEM.jpg


Although it's hard to determine where exactly the noise comes from, it doesn't seem to come from the case fans.

Any idea of the likely cause and how to fix it?
I'd use a pencil or something else non-metallic to block the fan blade on each fan for a couple seconds, one at a time, to see if the noise stops. It's also a possibility the power supply is vibrating on the bottom of the case. Be careful sticking your hands in there. Safety first.
 

novathunder

Distinguished
Dec 31, 2007
16
3
18,515
I'm a bit scared to stick a pencil in the fan blade while the computer is running to be honest, might it not damage the fan?
No it won't, fans does not spin fast enough plus they're made of plastic. You can do it with you're finger if you're no kid (just kidding don't take it badly please 😋) it surprises more than it hurts. I do it with the index but you can use your thumb it's more robust you won't feel it, promise 😃 Archaic59 is right though you have to stop them one at a time and see if the vibration goes away. To my ear it looks like a cable in fan blade's path or worse yet, a dying fan. Tend to think it's coming out a fan. Also don't forget to try the power supply fan and graphic card fans as well, one of them is the culprit.
 
Solution

draikin1

Reputable
Jun 19, 2020
19
0
4,510
No it won't, fans does not spin fast enough plus they're made of plastic. You can do it with you're finger if you're no kid (just kidding don't take it badly please 😋) it surprises more than it hurts. I do it with the index but you can use your thumb it's more robust you won't feel it, promise 😃 Archaic59 is right though you have to stop them one at a time and see if the vibration goes away. To my ear it looks like a cable in fan blade's path or worse yet, a dying fan. Tend to think it's coming out a fan. Also don't forget to try the power supply fan and graphic card fans as well, one of them is the culprit.

Thanks!!