Asus P9X79 Pro fan problems

[ocirion]

Hi

I am having fan problems and I think its down to the MB but I'm not 100 % sure.

Spec is:

Intel i7 3820
Asus P9X79 Pro
Crucial Ballistix Elite 16GB (4x4GB)
EVGA Nvidia GTX 560 Ti 448
Samsung 830 256GB SSD
WD 1TB Green Caviar
Coolermaster 212 EVO
2x Akasa FN-058 120mm case fans
Corsair Carbide 500R case
Corsair HX750 PSU

I originally tried 2 Gigabyte X79 UD3 boards, but both resulted in 1 of the Akasa fans not spinning at all on sys fan header 1. Figured they were faulty and decided then to switch to Asus P9X79 Pro. The first one had a faulty dimm slot, and now I am on MB number 4!

This time, I have intermittent CPU fan errors (which I see can be resolved by lowering the min RPM speed in BIOS) but the main problem I now have is the 2 Akasa fans are not picked up in the bios. Additionally one of these spins very slowly when connected to one of the chassis fan headers (confirmed its not the fan by switching fan connections). The one fan that does spin quicly is connected to CPU OPT fan, and the rear exhaust fan spins just fine connected to another chassis fan point.

I am now thinking its possibly PSU or something else. Can it be that I'm stuck with a 4th faulty MB?!?

Any suggestions or ideas would be most welcome

Michael

I have tried switching which fan header on the MB they are connected to

 

[ocirion]

An update:

I disconnected the chassis fan from CPU_OPT and connected it to one of the chassis fan headers. Both top chassis fans (Akasa) then ran at a slow speed and were invisible in the bios.

Then tried switching off Q-Fan for all chassis fan connections and restarting, sure enough, both are now visible, constantly spinning at +/- 1200rpm. So it seems the motherboard does detect them but just doesn't want to handle auto-adjusting the speed.

I am not sure why they wouldn't work with Q-Fan, as they are PWM fans (Akasa AK-FN058). The bios is updated to the latest. Is there a compatibility list for Q-Fan on whats supposed to work with it ? or do I just have to wait till another bios update fixes it ?

The rear exhaust fan that came with the case, seems to work fine with Q-Fan.

The CPU fan error still appeared until I lowered the alarm setting to 400rpm. I am hoping the fan will spin faster when I put more of a load on it, as the temperature doesn't seem to get above 28C at the moment, but I've yet to even get an OS on it.

 

[ocirion]

Had a response from Asus to say that the P9X79 Pro chassis fan headers are not PWM (?!) only the CPU headers are.

I've asked for clarification as these are 4 pin headers, and are advertised as PWM.