CM 212+ fan runs only at top speed

[lennyh]

The fan on my Cooler Master Hyper 212 Plus has just started running only at top speed (approx 2014) regardless of the CPU temp.

The MB is an ASUS M4A88T-V EVO/USB3 with a mildly o/c Phenom 1055T. The idle temp is 31C. Up until recently, the fan ran as expected, very slowly during idle and gradually changing speed up and down appropriately as the cpu temp varied.

Then, a few days ago, the fan began running only at top speed regardless of the CPU temp. No changes have been made to the system. No new parts, no BIOS changes, etc.

Any ideas? Is the problem likely being caused by a faulty fan, faulty MB, something else? Any ideas regarding how I might diagnose/fix this greatly appreciated.

 

[lehtv]

You could try going to BIOS and changing the fan profile. E.g. if it's set to not control RPM, set it so it will. If it is set to control RPM, disable that, restart the PC then enable it and see if that works.

Also you could check the fan cable head to confirm all the wires are properly attached so they make contact with the motherboard fan header.

 

[lennyh]

lehtv, thank you for your helpful response.

I went into the BIOS and checked the CPU Q-Fan Function. I have never explicitly set that, but noticed that it was set to Disabled (the default is Enabled). I then set the CPU Q-Fan Mode to Standard (also the default). It had been set to Turbo!. Saved and restarted and all is now AOK. Don't know how these ever got set to the non-default values.

Over the past few weeks, I experimented with some fan speed apps, but never (knowingly) changed anything. Wonder if one of them perhaps reached down into the BIOS and changed it.

Also, do you happen to know whether this BIOS function is intended to enable/disable the basic pwn control of the CPU fan as it has appeared to do in my case?

In any case, I'm good for now. Thank you for your help.

Lenny

 

[lehtv]

Glad that sorted it out

Also, do you happen to know whether this BIOS function is intended to enable/disable the basic pwn control of the CPU fan as it has appeared to do in my case?

Yes, that's exactly what Q-fan is for. I've got an Asus X58 board, been using the Q-fan function for a long time to PWM-control my CPU fan (idle ~ 500RPM, load ~1300RPM). When I originally bought this board, I had not set any Q-fan control and the CPU fan was at full speed. This went on for months, back then I was totally oblivious to what a proper PC should sound like when idling (hint: it shouldn't make sound). The CPU fan wasn't the only thing either - I had a noisy Antec 900 case, a noisy 4870X2, and a noisy PSU (in hindsight, it was probably faulty lol).

 

[lennyh]

Thank you for the added helpful information including the interesting and clarifying background experience.

 

[mnguyen84]

cool