Fans stuck at full speed and noisy

[Hassan_Bukhari]

Salam.. hi every one.

I have just bought an used pc hp 8000 elite sff. This working very well but fans(psu fan and chasisfan) running fast all the time. Slow down for 2 second somtimes when insert usb or run any program Then again fast.

Thermal paste applied. Bios updated and window too.. cleaned all parts.

Please help me.

[SDH]

Did you check that the fans were not turned up to high in BIOS.... bottom of the power section.  Most of us run our fans at the lowest setting.

[Hassan_Bukhari]

In bios setting is to minimum. Green jumper removed and i did not replaced.

[SDH]

With the more advanced HP workstations there is a fan control system that may detect temperatures being too high or even too low and at a certain threshold ramps up fan speeds because that is the safest thing to do.

That can falsely come from an "ambient air temperature" sensor going bad.  Try to figure it out from that angle.  It is a good sign that things are still running..... not sure if that even has such a sensor.

[Hassan_Bukhari]

Thats not a workstation.. hp elite 8000 sff pc. How to find and replace this sensor?

[Hassan_Bukhari]

Sir any other soution?

[DGroves]

on this model series  HP 4000/6000 sff and tower and 8000 elite the ambient temperature sensor is  in the power supply

http://h10032.www1.hp.com/ctg/Manual/c01960471

replacing the power supply should resolve your fan issue

from the HP service manual for this series:

4.5.4 Thermal Sensing and Cooling
All systems feature a variable-speed fan mounted as part of the processor heatsink assembly. All
systems also provide or support an auxiliary chassis fan. All fans are controlled through
temperature sensing logic on the system board and/or in the power supply. There are some
electrical differences between form factors and between some models, although the overall
functionally is the same. Typical cooling conditions include the following:
1. Normal—Low fan speed.
2. Hot processor—ASIC directs Speed Control logic to increase speed of fan(s).
3. Hot power supply—Power supply increases speed of fan(s).
4. Sleep state—Fan(s) turned off. Hot processor or power supply will result in starting fan(s).

[Hassan_Bukhari]

Thanks for your help and info. But i did not found any sensor in psu. Can you give me any picture? 

[DGroves]

i'm not going to show someone who is not qualified how to open a power supply which can be dangerous and lethal to people who have no idea what they are doing or looking for (sorry)

spend the 20.00 for a replacement supply, they are quite common on the USA ebay from numerous sellers and i'm sure one of them will ship to non us locations

[Hassan_Bukhari]

I have open whole psu yesterday. Here psu price will be 2000rs.. and i dont want spend money to it.. help with any clue..