Why does cpu fan keep running even when i shutdown


Nov 17, 2012
I have a problem. Even after i shutdown, my pc fans (all of them (case, CPU, Graphic, PSU)) still keeps running indefinately, i can still eject and close DVD drives, they aren't powered down!. But monitor is powered down. The leds in my case also remain on.


i5 2320 @ 3.00Ghz
12 gb ram
MSI H77MA-G43 motherboard
Nvidia GeFoce GTX 560
Windows 7 (64)



Oct 18, 2012
It could be either a motherboard or power supply issue. If you can get another power supply where you know you an return it than I would try that, if not than see if you can borrow a friends. Are the fans connected through the motherboard? If so then it's probably a motherboard issue. I've herd of fans taking a while to turn off (mine take a full minute) but never forever.


I was going to suggest exactly the same thing as maestro0428. Seems like a Windows problem at first, it could send a signal to the monitor to go in sleep mode, but not be able to fully complete its shutdown process afterwards.

I would try to boot on a CD or USB key with an OS on it (like BART PE or something) and shutdown from it to see if it does the same thing.


I had the same problem. Changed ACPI mode from S1 to S3 in BIOS Power Management and now it shuts down properly. It seemed like a windows problem because when I turned my Power supply off to get the fans to stop, Windows told me 'Windows wasn't shut down properly, do you want to enter the Safe mode?' Still, the BIOS setting removed the whole problem.


Jun 16, 2013
Ok Your computers power supply (PSU) is not powering off. The power supply is controlled by a green wire on the 24 pin connector (Usually The biggest connector on the right side of the motherboard) It is important to check that the cable and pins are connected.

I suggest that the power supply is functioning properly and that the motherboard has a defect. There is the simple process of switching off at the mains socket to fix the problem but I believe you would rather a standby situation where you only need to use the front panel switch.

To do this you may need to replace your motherboard so I would check the warranty, Otherwise consult your manufacturer to find a replacement board. If you are Technically able to replace a motherboard it is the cheapest option. Just ensure you know the exact type of motherboard currently within your system and find a suitable replacement.

I hope this helps but be sure to fully understand everything you need to do to ensure you do not damage your system further before attempting any repairs and watch out for Static Electricity when fiddling around the inside of your system.