Weird fan behaviour

[Powerpuncher]

Hey,

so I've been undervolting my CPU on the weekend and it seems to be stable at 1V. But I encountered a problem with my main CPU fan in the process of undervolting. It randomly ramps up to 100% and stays at 100% for a random amount of time (sometimes for hours) and then ramps down again to around 700-800 rpm (with no steps inbetween). I didn't change anything in the BIOS other than the CPU VCore. The temps are low, there is no CPU activity and there is no reason at all for the fan to ramp up.

 

 

What's most iritating is that everything worked normal before undervolting my CPU and now after, even if I set the VCore on auto again, the fan still ramps up to 100%.
I tried loading the default profile for the BIOS, but it didn't help and now I'm kind of clueless. Did I somehow manage to corrupt my BIOS?

It currently doesn't even ramp down anymore. And if it ramps down then only for a few seconds before it ramps up again.

Intel i5-4670 (With Spire TherMax Eclipse III cooler + Arctic MX-4)
Gigabyte Z87-D3HP
G.Skill Ares 8GB DDR3-1866
Gigabyte GeForce GTX 770 WindForce 3X OC
Cooler Master G600 600W

Already searched on google quite a bit, but couldn't find anything.

Regards,
Pp

[AfroStorm]

How many fans do you have on your cooler and what pins are they plugged into on the motherboard? YOu could also get a cable to undervolt your fans to 7v or 5v instead of the normal 12v. Then the 100% fan speed would not be as loud or fast.

[Powerpuncher]

There are two. With the pushing fan plugged into the main header and the pulling one plugged into the OPT header. All my case fans are plugged into a Bitfenix Recon fan controller.

[AfroStorm]

It could be the fan controller going bad, have you tried plugging the cpu fan into the cpu fan port? You could also try using a 7v spliting cable so both of the fans are plugged into the CPU fan connector.

[Powerpuncher]

No, you understood me wrong. The 2 CPU fans are plugged into the motherboard (it has 2 CPU fan headers). My 5 case fans are plugged into the recon.

[AfroStorm]

The motherboard won't like it but you can run the fans on the fan controller and have them on a set speed.

[Powerpuncher]

Well that's not and option since the controller only has 5 channels and all are used. And I rather want this issue fixed rather than working around it.

[AfroStorm]

Have you tried flashing the BIOS with a newer or current version? This is not reseting to defaults, this is flashing the BIOS ROM.

[Powerpuncher]

Okay I tried switching the fan headers. Now the pulling fan is plugged into the main CPU header and for some reason it seems to have fixed the issue. Don't ask me why...

Thanks for your help anyways!

 

Edit: Yes, I did update my BIOS, but it didn't work.