[ltp] T420 fan

Philipp Kern linux-thinkpad@linux-thinkpad.org
Sat, 9 Jun 2012 12:35:21 +0200


does anyone here own a T420? In normal use my laptop does to 70°C now, with
mainly just Firefox open. That's with kernel 3.2. Do you notice that the fan
actually blows much air on the rear left and possibly on the left top?

I know that the fan spins. I even hear it. When I pull it up to full-speed or
disengaged with fan control, I still don't notice air coming out, despite the
fan being insanely loud.

So I'm unsure if something's blocked, but I'm also unsure how to check that. If
I just remove the keyboard, nothing serious is visible.

I know that it only started recently, but I don't know what to pinpoint it to.
It's also possible that a recent BIOS upgrade (to 1.39, ECP: 1.18) is at fault.
Is it possible to downgrade the TP BIOS?

Kind regards
Philipp Kern