bootup vertilator fan failure error

[Tregory Pierce]

I have a hp Pavilion 8679F Desktop system. When I bootup I get the error:

Ventilator Fan Failure: Pc May overheat

I have checked the fans and they are all working. Is there a way to remove this error or bypass it so I can start my system? I am thankful for any suggestion.

[Ron Kinner · Accepted solution]

A fan has two functions. One obvious one is it spins and moves air. The second, lesser known function, is to generate a signal which indicates it is running. This signal is sent to the Motherboard where the CPU reads it and this is how it determines that the fan is running or not. It appears that either your fan no longer generates the required signal (perhaps replaced with an incorrect replacement?), the wire to the motherboard is broken/disconnected/plugged into the wrong connector, or the sensor on the motherboard is shot.

You should see 3 wires coming from your fan if it the correct type. The red and black provide +12v and ground to run the fan so the third wire is the signal line. The parts site calls for Cooling fan - 80mm x 80mm x 25mm, 3-wire, 12VDC, 0.30A (Delta model ASB0812HH) -$16.58

I see goldmine has them a lot cheaper:

www.goldmine-elec.com/pdf/241page43.pdf

www.delta.com.tw/products/dcfans/pdf/ASB808025.pdf is the spec on the fan. Note there are two options -R00 and -F00. Each one provides a different voltage output and unfortunately HP does not say which they use.

Some system will allow you to turn off this monitoring in the BIOS but it does not appear that yours does. (I wouldn't let you either - at least not until the warranty expired.;-) ).

After verifying that the wires are OK and plugged into the correct connector you could try changing the fan. (If you can't get the exact replacement at least avoid the fancy ones with LEDs. These sometimes pull too much power.)

Ron