Win7 RC + HP Pavilion dv6775us - weird CPU fan behavior

Greetings everyone!

Since forum search didn't help much I would like to start a separate thread.

Here is synopsis:

I have recently installed Windows 7 RC on my HP Pavilion dv6775us, everything works fine out of the box (HP driver for quick launch buttons and Nvidia drivers for video - rest from Microsoft via update engine), but there is weird issue with CPU fan.

Everytime when system starts, right in the moment when welcome screen appears CPU fan starts rotating at high speed. This lasts about 6-8 minutes after startup regardless of system load. CPU temp at this moment is about 35'C. After 6-8 minutes fan goes back to normal speed and works as intended. This happens every time I switch on/restart/wake the laptop.

I have updated system to the most recent BIOS, no change in behavior.

Really got no clue what to do, will appreciate any comments/suggestions.

Thanks in advance.

P.S. Here are the laptop specs if someone interested: Product Specifications*

Both my DV5 and DV7 do this, I have learned to live with it since it ramps back down again. The only thing I can think of is its a fail safe in the BIOS setting by HP. Since when I turn on the Laptop the chips start at the highest setting they have then ramp down the speed of the processor if its not needed to be at the highest setting so the fan runs at top speed to keep it from over heating. I was also looking in my BIOS and found an option for the CPU fan to Always on or off. I have not played with this option yet but it might have something to do with the fan running at full speed when booting or waking the machine.

Thanks for reply!

Well, the weird thing is that when I power on the laptop, fan starts at high speed, but during windows startup it goes back to normal and only when Welcome screen flashes up it increases speed again...

b787 said:

Thanks for reply!

Well, the weird thing is that when I power on the laptop, fan starts at high speed, but during windows startup it goes back to normal and only when Welcome screen flashes up it increases speed again...

b787
First welcome to SF. Hp's aren't the only ones. Dells do as well. A search on HP's site cites sereral different causes (provide serial number to them). 35c(~95f) may be the threshold of turn on and turn off of the fan. here is the page Product Specifications

Hope this helps somewhat

Ken