Dell Studio 1555 fan unresponsive.. or is it?

[kisk]

Have a laptop (model in title) and its experiencing overheating and cutoff due to the fan not running -- in post, boot, windows, anything. Pulled the old fan out. Bearings are fine, it spins freely and the dust buildup wasn't bad at all. Regardless, still purchased a new fan and put it in + new thermal paste on the cpu -- same problem.

I decided to update the bios on it thinking it was a cmos problem. Don't worry, I had the laptop set on one of our AC vents that blows frigid air..

Now here's the funny thing -- when I was installing the BIOS via the dell updater in windows, the fan turned on full blast -- guess this a feature of the updater to avoid overheating/shutoff during the flash. After the restart/bios load defaults, the problem still exists.

Was wondering if any of you have heard of this before I let her know she needs a new mobo.

Thx!

 

[Larry Sabo]

I have had that problem with a number of Dell laptops, including the 6400 I'm using now. Also updated to latest BIOS but it makes no difference. I resort to I8kfan to force the fan on full speed when it gets too hot, as it just did -- getting to 70C after coming out of sleep mode. Sometimes the cpu fan will come on at 60C without I8kfan and temps stabilize on their own. I've also replaced the fan on another Dell that had these symptoms with no joy. No idea what the underlying cause is, but suspect it's related to power management. Would love to find a definitive solution.

 

[shamrin]

I've had this a few times with Dells as well. As I recall, the root cause is in the temperature sensing so the computer doesn't know it is overheating. Larry has the right solution to this, use I8Kfan to either run the unit at a constant rate or you can get tricky and base the speed on the temp of the CPU.

There are some peculiarities to this solution, for example, you need to make the machine autologon to the desktop so that it does not stop on the welcome screen as the computer will heat up but the fan won't actuate because I8KFan only starts at the desktop. Also, watch out if you have multiple users.

 

[kisk]

Sorry for taking so long to respond.. been busy!! Seems the bios update did get the fan working again. Not sure if that directly was the fix or something else, but its working as it should now. Thanks for the tip about the dell fan app too -- never seen that before but have added it to my stick.

Thanks!