Lost fan control - won't slow down!

[Sacha D]

Hey team.  After playing around a bit with my PC, my chassis fans won't slow down or stop....they're running at near maximum and I can't figure it out.  I've tried BIOS reset and Qfan control, power downs, resetting plugs, and using Fan Xpert to set my performance (see screenshots for measured fan RPM's as labelled respectively).  3x front stock fans from P500A, and 1x rear exahust QL140.  CPU fans (also QL140) as far as I know run as normal, all the time albeit at reduced speeds.

 

The only thing that lead to this was doing some mild overclocking (tested in my old case previously, this was a re-OC in the new P500A) and I found that I was severely overheating (wasn't as obvious at stock settings in games).  So I remounted my AIO with fresh paste and it's fine now.

 

P500A case housing Z490-E Strix supported by 32Gb Tridenz 3200 CL 16 and i7-10700K CPU running stock cooled by NZXT X63 AIO with QL series fans.

 

-Sacha

[Bombastinator]

Howdy and welcome  

 

Possible pwm problem would be my guess.  
 

pwm stands for pulse width modulation.
fan speed on four wire fans is controlled by the fourth pwm wire which is usually yellow. If you got 3 wire fans they need to be controlled by putting them on a splitter with a four wire fan or by using a fan speed controller of some type. If you’ve got four pin fans but speed is still wonky perhaps there’s a broken yellow wire. 

[Sacha D]

2 hours ago, Bombastinator said:

Howdy and welcome  

 

Possible pwm problem would be my guess.  
 

pwm stands for pulse width modulation.
fan speed on four wire fans is controlled by the fourth pwm wire which is usually yellow. If you got 3 wire fans they need to be controlled by putting them on a splitter with a four wire fan or by using a fan speed controller of some type. If you’ve got four pin fans but speed is still wonky perhaps there’s a broken yellow wire. 

 

The Corsair QL140 rear exahust is a PWM fan, but the front 3 case fans are not (3-wire). All are connected to a 4-wire fan hub which runs to CHA_FAN 2.  Nothing has changed other than the overclocking attempt mentioned before.

 

Since this message, I have uninstalled and reinstalled AI Suite and Intel XTU, updated drivers and software, and installed the latest BIOS. No change.

 

[Bombastinator]

6 minutes ago, Sacha D said:

 

The Corsair QL140 rear exahust is a PWM fan, but the front 3 case fans are not (3-wire). All are connected to a 4-wire fan hub which runs to CHA_FAN 2.  Nothing has changed other than the overclocking attempt mentioned before.

 

Since this message, I have uninstalled and reinstalled AI Suite and Intel XTU, updated drivers and software, and installed the latest BIOS. No change.

 

My suspicion is the fan hub then. It might be an issue with the fan hub needing the right software or something.  Fan hubs have gotten weird since the great rgb brewhaha Could try plugging the hub into a different port or seeing if that model requires software or something.  Testing the rear fan individually bypassing the hub might possibly be worthwhile. 

Edited December 16, 2020 by Bombastinator

[Sacha D]

8 minutes ago, Bombastinator said:

My suspicion is the fan hub then. It might be an issue with the fan hub needing the right software or something.  Fan hubs have gotten weird since the great rgb brewhaha Could try plugging the hub into a different port or seeing if that model requires software or something.  Testing the rear fan individually bypassing the hub might possibly be worthwhile. 

Nah, it's just a splitter....no controls.

 

Alas, I figured out my probelm.  Firstly, BIOS defaults to PWM mode for the fans.  Secondly, I had correctly set my fans to DC mode, but that wasn't saved in my BIOS user profile.  So when I changed profiles during my overclocking, they went back to PWM.  However, the caveat was that when selecting DC Mode within bios during my troubleshooting, it didn't change the fan speeds nor did it reflect 0 RPM in the graph....so I was lost as to the fact that I was changing the right setting.