Fan is RELENTLESS on my 6400!

I just realized that I actually have an FN key on my keyboard.
I tried the FN+Z but nothing happened.

Am I supposed to see an immediate change in fan speed?

 

Only if the current fan speed is higher than needed for the current temperature level. Fn+Z doesn't lower the fan speed, it just calibrates the fan speed to match the current temperature.

The Fn+Z combination is useful to stop the fan from running the fan at high speed long after the laptop has cooled down. But it doesn't help if the BIOS is programmed to keep the fan at high speed on moderate temperatures.

If you want to try if Fn+Z works on your laptop you can start some CPU intensive task like calculating 99999999! in two instances of Windows Calculator. When the fan kicks in, stop the calculation and let the laptop cool down a bit. If the fan doesn't lower its speed after a while, try Fn+Z.

Örjan

 

On my M6400 Covet it sends all screens including external ones into power save, with backlight off. It turns them back on if it gets an input event. Seems identical to windows powering down the screen after a certain amount of time.

 

My fan issue has just taken a turn for the worse.
I put my laptop to sleep and hour ago and the fan is still going?

Im about a day or two away from chucking this thing out of my 15th story window...

 

Then it's definitely time to ask Dell to fix it: Peculiar fan operation while running may be by (bad) design, but continuing to run during sleep suggests something is wrong.

John