Question All fans running at max speed

[Fraspp]

Hello!

I'm pretty stumped by a problem that arise with my kids computer yesterday.

There was a thunderstorm so we unplugged it to be more safe and less sorry.

After starting the PC (not old Lenovo loq small tower) all the fans started blowing at max speed.

I've tried all the settings I can think of, tried using third party applications to slow them down, flashed a new bios and reset that to defaults and fiddled around with balance and performance mode with no results. Restored/reinstalled the computer. Even cleared the cmos by removing the battery for 15 minutes. Messed around in Lenovo vantage with nothing positive coming out of it...

During the bios update procedure, the fans behaved normally, so just running slowly which leads me to believe they is at least some hope.

I've opened the case and verified that ALL fans are running mad with the possible exception of the GPU. It was hard to tell with the surrounding propeller planes.

It has warranty but that must likely involves driving it 100km/160 miles to hand it over, so I'd rather avoid that if possible.

Any ideas are appreciated

Best regards /

Fredrik

 

[Lutfij]

Welcome to the forums, newcomer!

When you connected the PC back to a wall outlet, did you notice the time in BIOS was off?

(not old Lenovo loq small tower)
Got an SKU to your prebuild machine? Is this what you have?

 

[Fraspp]

No, didn't think about that tbh. I pretty immediately started to restore it and noticed some oddities. Restoring from windows for stuck at 62%. Entering bios from advanced restart didn't work. Found some command line reboot to bios which also didn't work.

Had to restore from safe mode, after that the PC returned to normal minus the fans and advanced reboot to bios/uefi started working.

It also wanted to do a TCM? restore during the restore process which I allowed.

I'm a little bit thinking virus, but there is no load on anything, both CPU and memory load seem fine. Also, temps are low (30-40 C and what I think is the CPU at around 60 C).

 

[Paperdoc]

Check on this detail. IF your fans are all or mostly 3-pin, AND the mobo headers have 4 pins, this might be your problem.

If you plug a 3-pin fan into a 4-pin header that really IS using the new PWM Mode of control signals, that fan will always run full speed. Now, most mobos recently have ONLY 4-pin fan headers, BUT in BIOS Setup for each such header you are offered a choice of which signal type it sends out to its fan. The choices will be PWM Mode or Voltage Control Mode (aka DC Mode), and maybe an Automatic Mode. Most mobos come with these all set to PWM Mode. Because you have updated the BIOS, that option will have been reset that way, to PWM Mode, for all fan headers. Go into BIOS Setup and for each fan header, check its MODE setting. Any that are feeding a 3-pin fan needs to be changed to Voltage or DC Mode.

 

[Fraspp]

Thank you for your reply!

However, the problem started before updating the bios, I was hoping to update my way out of it Also, the Lenovo bios is really limited - all I can do is chose between performance and balance mode so no luck there. Also, since I never changed anything physically in the computer, I don't see how number of pins should affect anything.

 

[Paperdoc]

The reason I posted that was this. You report that, before the storm interruption, fans all appeared to run at reasonable speed. However, immediately after they all appear to run full speed no matter how you set them. One way that can happen is if the fans are the older Voltage Control Mode fans with THREE wires out to a connector with three holes but they are plugged into a 4-pin fan header that is set to send out signals in the newer 4-pin PWM Mode. You may nbot have seen this in this form, so may not recognize. Among the options for configuring a fan header, one is the PROFILE - the strategy the system uses to decide on the basis o a temperature measurement just what the fan speed should be. Other options under Profile include fixed full speed, fixed lower speed, or sometimes a fixed speed you specify. Separate from that is the header signal MODE, which is the type if signal sent out to achieve what the Profile asks for. A 3-pin header can send out ONLY the older Voltage Control Mode signals. Most 4-pin headers now can be set by YOU in BIOS Setup to send EITHER those OR the newer 4-pin PWM Mode signals. IF the header sends out older Voltage Control Mode (aka DC Mode signals, BOTH fan designs should have their speed controlled that way and WILL do what the Profile decision requests. But if the signals are sent out in PWM Mode, any 3-pin fan cannot respond to that properly and will always run full speed, whereas any 4-pin fan CAN have its speed controlled that way. That is how header pin count AND header option setting for MODE makes a difference.

As I said, IF your fans are 3-pin models, and IF the mobo fan headers are 4-pin, this MIGHT cause your symptoms, especially because the BIOS Update would set all the fan headers by default to the 4-pin new PWM Mode.