Problem after first PC build

[nandz]

Hi all,

I completed my first build a few days ago and everything seems to be running fine apart from one problem where I may need to RMA the motherboard, after reading around.

The actual issue is everytime I shut down the system, via the power button on the chassis or via Windows OS, everything will power off apart from the fans - case fans and CPU fans (push, pull) - all will continue to spin at full speed. The only way I can stop them from spinning is by switching off the switch on the PSU. When I turn the PSU switch back on, an LED on the motherboard will light up green indicating that the system is on but the fans will not begin to spin until I turn on the system. This is when the fans will kick into high gear and run at full speed until I flick the power switch on the PSU off again.

This seems to be a fairly common problem others have had but some of the solutions they've found haven't solved the problem for me. I've tried disabling power options, updating the BIOS, resetting to BIOS defaults and changing the fan cables around from the PSU connectors to motherboard FAN connectors. This is all fairly new to me as this is my first build so I'm not too knowledgable on certain BIOS settings.

My system specs:

Intel Core i5 750
ASUS P7P55D-E PRO
G.Skill Eco Series 4GB
Samsung F3 1TB
XFX ATI 5850
CM 690ii Advanced
Prolimatech Megahalems with 2x Scythe Gentle Typhoon Fans @ 1850RPM
Corsair TX750w

Some things that may be of importance:

- When I shut down the system and the fans continue to spin, the CPU_LED lights up red and stays lit until I turn off the PSU. This LED lights up for a few seconds on boot up but then switches off and stays off until I shut down the PC, at which point it lights up.

- When I shut down the system and the fans continue to spin, the HDD activity light on the top of the chassis turns solid red, with no flashing, although the HDD is powered off, by the sounds of it. The power light next to the HDD activity light on the chassis, however, is off.

I've come across a post made by another owner of the same board who had the same problem but solved it by getting it replaced by ASUS. Looks like I mught need to do the same although I've come across posts by others who have managed to solve the issue themselves by different methods. The red CPU_LED lighting up after shutdown looks like it may be linked to the problem but I say that with no experience or knowledge on the subject.

Is there anything else I could try or change before I return it? Is it even the motherboard at fault or likely another part?

Any help would be greatly appreciated.

Cheers

 

[avatar_raq]

If you hook-up your fans to the PSU directly, will they continue to spin after shut down? You weren't clear about this...If they stop, it's definitely the mobo, time to RMA !!

 

[jsc]

When I turn the PSU switch back on, an LED on the motherboard will light up green indicating that the system is on but the fans will not begin to spin until I turn on the system.

This much of what you are seeing is normal. The motherboard LED is illuminated by the small (10 - 15 watt), always on standby power supply.

The rest of it, I would suspect your better than average PSU or the motherboard.

 

[nandz]

Thanks for the replies avatar_raq and jsc.

I've just tried hooking up a single fan directly to the PSU and turning it on via the paperclip method. The fan spins in both the PSU and the single case fan attached to a 4 pin molex. I then switch off the power supply by the switch on the PSU but the fans still continue to spin, so really, the PSU doesn't power off unless I switch it off from the mains. That's funny because I could switch it off from the switch on the Corsair when the the fans kept spinning after shutdown; now the switch on the PSU doesn't even stop the fans from spinning. What the hell? :lol: Does this point to a faulty PSU?

 

[avatar_raq]

It sure does.