Fan strange behavior with UEFI Firmware 1.03

I have two UDOO X86 boards and today I upgraded their UEFI Firmware from 1.02 to 1.03. Both completed the upgrade successfully and their BIOS settings are set to the default. However, the fan on one board now runs all the time while on the other board the fan stops once Ubuntu starts booting up. Does anyone have any idea why this distinct behavior?

 

Are they both on default settings? F9 in Uefi settings.
They both should switch off after the OS starts unless the temperature is so high that the fan has to run.
What does the cpu temperature sensors say (run "sensors")?

 

Yes, they both are on default settings. Notice that updating the UEFI BIOS to a newer version will restore the factory default configuration. However, I still went to the UEFI settings and pressed F9.
sensors report these values for the one running the fan all the time:

coretemp-isa-0000
Adapter: ISA adapter
Core 0: +34.0°C (high = +90.0°C, crit = +90.0°C)
Core 1: +34.0°C (high = +90.0°C, crit = +90.0°C)
Core 2: +28.0°C (high = +90.0°C, crit = +90.0°C)
Core 3: +33.0°C (high = +90.0°C, crit = +90.0°C)
---------------------------------------------------------------------------------------

And this for the one that stops when Ubuntu boots up:

coretemp-isa-0000
Adapter: ISA adapter
Core 0: +57.0°C (high = +90.0°C, crit = +90.0°C)
Core 1: +56.0°C (high = +90.0°C, crit = +90.0°C)
Core 2: +51.0°C (high = +90.0°C, crit = +90.0°C)
Core 3: +45.0°C (high = +90.0°C, crit = +90.0°C)
---------------------------------------------------------------------------------------

 

That is strange. I see no other option for you than to contact customer care and open a ticket. https://www.udoo.org/customer-care/

 

reset all settings in BIOS. I ran into the same problem.

 

I did that. In any case, all setting are reset to factory defaults when the UEFI BIOS is updated to a newer version.

 

I assumed so as well, and had erratic fan control until I reset all BIOS settings. It didn't work for you, sorry...

 

I actually need to have the fan running all the time. That was the main reason for me to upgrade to 1.03 since someone posted that result after he did the upgrade. One of UDOO is already doing that so maybe the question now is, does anyone know the specific setting that forces the fan to run all the time? Thanks!

 

See paragraph 4.5.3 of the hardware user manual (pdf) that you can download here: https://www.udoo.org/docs-x86/Hardware_Reference/Resources.html