CPU Fans Don't Spin Unless "hand started"

[darevicius]

Hi,guys.After replacing AMD CPU and CPU fan(Zalman cnps10x performa,900 ~ 2,000RPM,PVM,connected to 12V 4 pin MB cpu fan header),CPU fan sometimes doesn't start on booting in the morning.It starts just after I turn of PC and start again or touch it with my hands.In BIOS power settings CPU Q-Fan Control is enabled,CPU Fan Speed Low limit set to 200 RPM.Before I had no problem with stock AMD CPU fan .Is something wrong with fan bearing?Thanks in advance.

 

[chegalhavara]

Can be a problem with the bearings or they are just dirty. Try cleaning it with compressed air. If it doesn't help, maybe it is time to replace it. If it is new, send it to Warranty.

 

[darevicius]

Can be a problem with the bearings or they are just dirty. Try cleaning it with compressed air. If it doesn't help, maybe it is time to replace it. If it is new, send it to Warranty.

I will try

 

[darevicius]

Can be a problem with the bearings or they are just dirty. Try cleaning it with compressed air. If it doesn't help, maybe it is time to replace it. If it is new, send it to Warranty.

what fan do you suggest for replacement ?

 

[chegalhavara]

Not shure if you can replace it. I have the cnps 9900max and I cant replace the fan. When it goes to cooler heaven I have to buy a whole new cooler.
The Evo 212 is a popular choice if you are not a hardcore overclocker.

 

[Paperdoc]

Tell us exactly what mobo you have so we can look at its manual. You say, "CPU Fan Speed Low limit set to 200 RPM", but I suspect that is the setting for the alarm limit, not the actual minimum speed your mobo will try to use. Anyway, the specs for the fan on that cooler suggest it is designed to run between 900 and 2000 rpm. So, if you mobo's CPU fan control system is configured to use a much lower minimum speed, it might not be enough to start it up when cold. Looking at the manual may tell us how to adjust that setting.

 

[darevicius]

Tell us exactly what mobo you have so we can look at its manual. You say, "CPU Fan Speed Low limit set to 200 RPM", but I suspect that is the setting for the alarm limit, not the actual minimum speed your mobo will try to use. Anyway, the specs for the fan on that cooler suggest it is designed to run between 900 and 2000 rpm. So, if you mobo's CPU fan control system is configured to use a much lower minimum speed, it might not be enough to start it up when cold. Looking at the manual may tell us how to adjust that setting.

Yes 200 is lower speed limit alarm,when windows boots sometimes I get a message cpu fan error,my mobo is Asus M5A78L-M LX V2

 

[Zerk2012]

Tell us exactly what mobo you have so we can look at its manual. You say, "CPU Fan Speed Low limit set to 200 RPM", but I suspect that is the setting for the alarm limit, not the actual minimum speed your mobo will try to use. Anyway, the specs for the fan on that cooler suggest it is designed to run between 900 and 2000 rpm. So, if you mobo's CPU fan control system is configured to use a much lower minimum speed, it might not be enough to start it up when cold. Looking at the manual may tell us how to adjust that setting.

Yes 200 is lower speed limit alarm,when windows boots sometimes I get a message cpu fan error,my mobo is Asus M5A78L-M LX V2

You have the low setting to low to start the fan you should set all the CPU fan settings back to stock and let the board controll it as needed.
Fan 1 might start on 5 volts but anouther fan might not start till 7 volts.

 

[chegalhavara]

Tell us exactly what mobo you have so we can look at its manual. You say, "CPU Fan Speed Low limit set to 200 RPM", but I suspect that is the setting for the alarm limit, not the actual minimum speed your mobo will try to use. Anyway, the specs for the fan on that cooler suggest it is designed to run between 900 and 2000 rpm. So, if you mobo's CPU fan control system is configured to use a much lower minimum speed, it might not be enough to start it up when cold. Looking at the manual may tell us how to adjust that setting.

Exactly. And most mobos only use speeds from 50% up allthough the fan allows a lower minimim speed.
Check the UEFI to see if the fancontrol is set to AUTO. If its not, you should set it to auto.

 

[darevicius]

But I didn't change anything in bios after I replaced cpu,only cpu fan connected to mb,rear case fan connected to psu via molex

 

[chegalhavara]

But I didn't change anything in bios after I replaced cpu,only cpu fan connected to mb,rear case fan connected to psu via molex

Even if you didnt change anything, check it, just in case it is set to manual or some profile. Make shure it is set to Auto.

 

[Paperdoc]

OK, your connections seem simple. Only the CPU fan on your Zalman cooler is automatically controlled by the CPU_FAN header it is plugged into. And that header definitely should work with the 4-pin PWM-style fan it has. You indicate that you have only one case ventilation fan, and it is not being automatically controlled by the mobo CHA_FAN header; it is connected to a fixed 12 VDC supply from the PSU.

It is possible that the signals being fed to the CPU cooler at start-up are too low to allow it to start up properly. However, I see no place in your mobo manual that allows you to change that configuration. Just to be sure, you should check the condition of the fan on the Zalman cooler. With the system shut off, gently push the fan blades to spin the fan. If it turns easily and keeps spinning while it slows down slowly, your fan is just fine. If it is hard to turn, or stops almost immediately when you spin it by finger, the fan's bearings may be worn out.

Regarding the items to check that others have pointed out, they are on p. 2-18 of your manual. The "CPU Q-Fan Function" must be "Enabled", and the "CPU Q-Fan Mode" should be "Standard". If you have to change either of them, remember to SAVE and EXIT from BIOS Setup so your changes are retained.

 

[darevicius]

Ok,guys.CPU Q-Fan Function was set to "Enabled", and the "CPU Q-Fan Mode" to"Standard" before.Fan blades turn easily and keep spinning,fan is ok.This morning I turned pc on and the same,needed to help with the hand to start spinning.So I can't find the problem.I read MB manual 2.18 few days ago.

 

[Paperdoc]

I can only make two additional suggestions. It could be neither of these will work, but here we are.

1. On the CD that came with your mobo, check for a utility to monitor and adjust your fan systems. There is usually something like that on the CD, and it's an application that runs under Windows. Using that, sometimes you have the ability to change the details of how the automatic fan control system operates. That MAY include a setting for the minimum speed it will use for your CPU cooling fan.

2. If you can't change that, you may be forced to live with the situation. While it is not ideal, it may be tolerable. What should be happening is that, even though the fan does not start up right away, it does start up shortly after as the CPU heats up and requires more cooling. Is that happening? If it is, you MIGHT still have a related problem. SOME mobos monitor that CPU fan closely and take quick action if it appears not to be operating, as yours is doing. That action often involves putting out a warning message about fan failure (which you have seen sometimes) and then shutting down the entire system without even waiting for the CPU temperature to get too high. IF your system shuts itself down before the fan start up, you can change the BIOS setting for the fan's minimum speed alarm system to IGNORE that fan signal, and then it won't issue warnings and shut you down. BUT this means that you are defeating this protection system designed to detect complete fan failure. It still leaves in operation the other protection system based on the actual temperature measure inside the CPU chip.

 

[Paperdoc]

Thanks for Best Solution.