Asus UX31A fan run full speed after replacing a motherboard

[Semantha]

Fan is running full speed all the time, as soon ux31a is power on fan run full speed.
Try several programs like SpeedFan or NoteBookFanControl but no help. Programs discover the fan, speed, temperature but refuses to adjust speed according
to temperature.
I updated the Bios to 219 without progress.
This is the job of a special chip which does not look to work !

Then I cleaned it including heatsink grid and put thermal past/Temperature stay between 40° and 50° and fan is running full speed all the time as soon I push power button.

Then I flashed this « UX31a Bios mod », and laptop is still alive !! This is good news!
Pressing F2 with power button display BIOS infos, and says BIOS 219 which is the one which was installed before update.
There is a new extra arrow under “Access level” when selected display about 100 parameters.
I don’t know how to go ahead from here.
There are some of these parameters related to thermal temperature and fan.
They are enable, set with correct values, nothing wrong to what I can see.
I did not play with them, I am a bit afraid.

Booting laptop load Window 10 as before and fan is always running full speed.
SpeedFan shows same infos as before bios update.

This action did not improve this fan issue.

I received the new fan, installed but problem remain.
Fan run full speed and it is annoying, machine is unusable in a quiet room, too noisy.

I do not see any thermal sensor, is there a way to know why it is running full speed all the time?

 

[webworkings]

When you changed the motherboard, did you use the same fan that you had before? Have you checked the thermal paste to make sure it isn't old, or lacking enough?

Worst case scenario, you need to replace the fan.