T580 fan starts running moment its turned on

[rotterdam]

T580 with below specs has the fan running at full speed from the moment its turned on. Therefore it can't be heat. Any idea what it could be?

Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz (1.80 GHz)
Win 11 Professional
16 GB RAM

[dcfbf]

Is the fan making any strange noises or have you spilled any water on or near it?

Most likely the CPU is overheating due to the heatsink not making proper contact with it.
Symptoms of this are:
High fan speeds even while doing nothing
No heat coming from the vents even though the fans are running
Stutters during usage from the CPU thermal throttling

You can check if this is the case using hwmonitor or hwinfo and looking for CPU core temperatures.
If this is the case, change the thermal paste.
If the issue persists, replace the heatsink.

But if it really is not the temperature, it could be a fan issue or a motherboard issue.
You can try unplugging and replugging in the fan connector

[rotterdam]

Hi dcfbf,

No, no water was spilled or other strange noises otherwise.

I'll monitor it with hwmonitor or hwinfo and report back in a few days.

[ZaZ]

BIOS update? I had a similar issue with my X220, which I bought new the first day. Lenovo sent ne a new heatsink with fan and it was a problem no more.

[dr_st]

If the temperatures are fine, but the fan still runs at full speed non-stop, it may be that the PWM wire (in the fan or on the board) is faulty.

[rotterdam]

Update:

There was a BIOS update 2 days back and the fan seems to be ok now. Just comes on a few times for like 10-15 seconds for no apparent reason and randomly and then goes AWOL.

So looks ok now. Will post back if anything changes.