Built new rig with one CPU fan error message, help!

MDian · 11 Oct 2013 at 17:31

Built my new rig (4770k, bequiet! shadow cpu cooler, asus hero, 8gb corsair etc) and all seems ok, launched the initial bios information etc, but comes up with a CPU fan error. The fan on the CPU is running, albeit at about 480rpm based on a CPU temp of around 30c (not tested for long period).

Is this something I should be worried about? It does prompt to resolve a startup boot issue, but that might be because I don't yet have my SSD attached (didn't arrive today, visit to o/c tomorrow).

snips86x · 11 Oct 2013 at 19:50

Have you connected it to the CPU fan header? The error would indicate possibly not!

Glanza · 11 Oct 2013 at 19:55

You probably haven't attached a fan to the cpu fan header on your board, if you plan not too providing your temps are ok after a test you can disable the warning in your bios

Rainagul · 11 Oct 2013 at 21:12

I forgot the exact terminoligy but on the BIOS for asus boards, the lower limit for the CPU Fan is 600 rpm. Even if you have it plugged into the right header but the CPU fan is lower then the limit then it will cause the fan error.

Either lower the limit to sub 400rpm on the BIOS or choose to ignore monitoring on the CPU fan on the BIOS.

Personally I lowered the limit rather than ignoring it.

Orcvader · 11 Oct 2013 at 21:31

I remember having the same problem on my old Asus Crosshair III during cold boots and thought it was probably the Asus board not giving the fan enough power to start up (although it still functions normally). I used a fan cable that allowed the fan to receive power directly from the PSU, but still controlled from the fan header and it seemed to stop the fan error problem from popping up.

Ragnahex · 11 Oct 2013 at 22:50

on my asus board i had to drop the cpu warning to 200 rpm with my hs and fan since on low temps the fan would run down to about 300 rpm. Worked fine after that. check your bios there should be an option to when you get the warning set it lower boot into windows and just double check your fan does kick up to full speed under load.

MDian · 12 Oct 2013 at 02:29

I assume it must be connected to the CPU fan header otherwise it wouldn't operate? On the Asus, it is plugged into CPU_FAN, not CPU_OPT which I assume is right. In Bios, it reads speeds of around 480rpm to 550rpm depending on the temp between 28C and 34C so I guess it is just regulating the speed to suit the temp.

I will try to find the option in bios to lower the rpm speed, though I can't recall seeing it when browsing the various options.

alex_123_fra · 12 Oct 2013 at 08:23

You need to go into fan control. Then there is an option that reads something like CPU Q fan control. Put the setting to "ignore" and you won't get the warning again.

MDian · 12 Oct 2013 at 15:43

Thanks, found it and adjusted it down to 400rpm as I still want it to monitor the temps for me. All up and running, no other faults, very happy. Now the fun of all the updates that come with a fresh windows install!!!!!