PSU Fan Stays On After Shutdown

**enf** · 09-02-09, 12:44 PM

Setup:
MOBO: ASUS M4A79 Deluxe AM3/AM2+/AM2 AMD 790FX ATX AMD Motherboard
CPU: AMD Phenom II X4 955 Black Edition Deneb 3.2GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor
CPU COOLER: Enzotech Extreme-X Rev.A 120mm 2 Ball CPU Cooler (I hope this thing fits...)
RAM: CORSAIR XMS2 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
VID CARD: EVGA 896-P3-1170-AR GeForce GTX 275 896MB 448-bit DDR3 PCI Express 2.0 x16
PSU: CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified
HDD: Western Digital VelociRaptor WD1500HLFS 150GB 10000 RPM 16MB Cache SATA 3.0Gb/s
HDD COOLER: MASSCOOL SYTRIN Kuformula SHF1 Ultra HDD Cooler
CASE: COOLER MASTER HAF 932 RC-932-KKN1-GP Black Steel ATX Full Tower Computer Case
OS: Windows7 Home Premium x64

I didnt even notice it at first because the fan noise is so low, but when I shutdown my computer at nite, the exhaust fan on my PSU stays on. Not just for 10 min or so to cool down the PSU, but all nite. Ill come back in the morning and it will still be on. So far, I disabled any Wake-On-Peripherals in my Device Manager and in the BIOS, and enabled the Energy Star 5.0 PSU compliancy in BIOS but no dice. Im thinking it has something to do with the mobo and not the PSU.

It cant be good for the fan to stay on forever right? If so, I dont mind it staying on, but Im sure thats not the case. Thats more just me hoping so I dont have to RMA something.

**HeavyG** · 09-02-09, 09:21 PM

Do you have a different PSU? If so, try swapping it and see what happens.

I really don't know what would cause this. Doesn't sound like it is the Motherboard. If the PC turns off, then then motherboard is doing it's job. Sounds like the PSU is "on the fritz".

**finc.hairy** · 09-06-09, 01:13 PM

My last 600W Enermax noisetaker used to stay on for 10 - 15 min after power off; it had something to do with a cool down feature of the PSU.

Maybe yours does too. You might want to get your hands on a PSU tester such as this one http://www.pcper.com/article.php?aid=246 and make sure it's good. Though it may look fine now, it could be the start of something else. Maybe google it as best you can?

Testers are cheap and very useful, can save you many hours, sweat and tears troubleshooting your hardware nightmares.

Good luck!

**enf** · 09-09-09, 01:45 AM

HAZA!

http://www.tomshardware.com/forum/26...ndows-shutdown

"Click “Start”, on “Computer” click right mouse button and select “Properties”, click “Device Manager”, select “IEEE 1394 Bus Host Controllers” group, only contains one device called “VIA 1394 OHCI Compilant Host COntroller” on that click right mouse button and select “Properties”, select “Power Management” tab, and finally check the “Allow the computer to tur off this device to save power” box!
That’s all folks. After that the computer power down normally every time."

Im shutting down for the nite now so Ill see if it works and post back tomorrow.

**HeavyG** · 09-09-09, 11:24 AM

So...?

**Kanati** · 09-09-09, 02:37 PM

I think he must have shut down permanently.

**enf** · 09-09-09, 03:46 PM

No dice...

But me thinks this brings me closer to a solution. I have one of the first generation MyBook's hooked up with regular USB so Im thinking its that because when the fan didnt shut off, I flipped the PSU power switch off and then on to stop the fan and the MyBook turned on with the computer off. So Im going to disconnect it before shutting down and see if that helps.

**Bunni** · 09-09-09, 03:55 PM

hmm, ironically, ive always had my psus still power the usb slots when the rest of the computer is off, phone still charges, keyboard will stay on (recently set it to turn off for windows shutdowns)