Case Fan problem!

parrot1553

Honorable
Apr 5, 2012
40
0
10,530
When I power up my pc or resume from sleep,one of my case fans is very noisy and runs at 200rpm only,after about 5minutes while the pc is still running,the fan slowly becomes more and more silent and reaches 1200rpm(its rated speed) and is fine after that,until the next time I start my pc or resume from shutdown...also if I only restart pc,it works fine.Is the fan failing? can someone tell me whats going on..I tried connecting it to the psu and on the mobo 3pin header,same issue.I have 4 other 120mm fans running at 1200rpm without any problems.Will a 7v mod on the fan fix the issue? also what happens if I connect a 7v and 12v fan on the same molex cable and then to psu?
 
Sounds like the fan controller (inside the fan) is faulty. At a guess, stepping it down to 7V it will do the same thing, just at lower speeds - only way to know though is to try it. If you connect a 7V and 12V to the PSU (via splitter with step-down adapter, Molex, etc), both fans will run at the max RPM for their respective voltage levels. If you're going to use the 7V mod vs a step-down, if you've got an older and/or crappy PSU it may not like it. I would recommend disconnecting power to the rest of the system and try the fans by themselves (using the PSU paperclip trick) before using that setup with the rest of your system hooked up.
 

parrot1553

Honorable
Apr 5, 2012
40
0
10,530


the fan is not stuck



I have a 1000W powercolor PSU,not sure of the exact model,its 80+ efficiency,I have heard that its actually less safe if I only power a fan with the psu versus the full system..