Weird fan behaviour

[Trylo]

Hi!

 

For some time now I noticed that my CPU fan is running quite low. It's not a constant thing, sometimes it ramps up as it should, other times just ignores the CPU temp. Right nowmy CPU is at 74C and the fan should be around 2800rpm at this temperature, yet it's just sitting at 900rpm...

 

I checked BIOS and made sure the fan curve is correct.

Any ideas how to troubleshoot it?

 

[Vr2Io]

1. Double check the CPU fan correctly plug in mobo CPU fan socket.

 

2. In console, type "sensors", and post.

[Trylo]

11 hours ago, Vr2Io said:

1. Double check the CPU fan correctly plug in mobo CPU fan socket.

 

2. In console, type "sensors", and post.

The fan is correctly plugged.
Here is the sensors print (now the temp is lower, yet the rpm is higher):
 

root@NAS:~# sensors
asus_wmi_sensors-virtual-0
Adapter: Virtual device
CPU Core Voltage:          1.10 V  
+12V Voltage:             11.84 V  
+5V Voltage:               4.88 V  
3VSB Voltage:              3.33 V  
Array Fan:               1271 RPM
CPU Temperature:          +55.0°C  
Motherboard Temperature:  +35.0°C  

k10temp-pci-00c3
Adapter: PCI adapter
CPU Temp:     +55.0°C  

asusec-isa-0000
Adapter: ISA adapter
CPU Core:      1.09 V  
Chipset:      +51.0°C  
CPU:          +55.0°C  
MB Temp:      +35.0°C  
T_Sensor:     -40.0°C  
VRM:          +21.0°C  
CPU:          24.00 A  

 

[Trylo]

I'm not sure if there is connection, but I've just turned on my Windows VM and the RPM dorpped.

 

root@NAS:~# sensors
asus_wmi_sensors-virtual-0
Adapter: Virtual device
CPU Core Voltage:          1.08 V  
+12V Voltage:             11.84 V  
+5V Voltage:               4.88 V  
3VSB Voltage:              3.33 V  
Array Fan:                886 RPM
CPU Temperature:          +59.0°C  
Motherboard Temperature:  +35.0°C  

k10temp-pci-00c3
Adapter: PCI adapter
CPU Temp:     +59.6°C  

asusec-isa-0000
Adapter: ISA adapter
CPU Core:      1.09 V  
Chipset:      +52.0°C  
CPU:          +59.0°C  
MB Temp:      +35.0°C  
T_Sensor:     -40.0°C  
VRM:          +21.0°C  
CPU:          23.00 A  

 

[Vr2Io]

2 hours ago, Trylo said:

but I've just turned on my Windows VM and the RPM dorpped.

 

I never got VM will affect fan RPM, anyway pls also confirm if fan type were PWM ( have 4 wire ) then set BIOS fan mode to PWM for match.

It also weird no temperature sensor have big drop but RPM actually drop. Some fan have build-in temperature sensor, it will automatic adjust RPM, pls also check that.

Edited March 16, 2023 by Vr2Io

[Trylo]

I've checked. The CPU Fan is PWM and bios is set to PWM.