Hi there,

I've got this weird CPU fan error at boot for a couple of months now and it just popped up out of nowhere.

The mobo is an ASUS P5GDC deluxe with a Zalman HSF. Everything ran fine for a few months until the BIOS started acting up.

The fan is in fact spinning at its normal rpm, the temperatures are fine and the system is stable. Once booted by ignoring the BIOS CPU fan message with F1 I never run into any problems in XP whatsoever.

Any ideas how to get rid of this annoying BIOS message are welcome.

cheers
sol

P4 640, Zalman CNPS7700-Cu cooled
Asus P5GDC Deluxe
Asus nVidia 6200
Cubase, VSTi and other CPU hogs

Do you have the 3 wire fan system??
If memory serves me correct, it is a red, black and yellow wire. The red and black are for fan power... the yellow is a sensor wire that feeds back fan rpm signals to the bios. I would guess that for some reason the bios is not getting this signal.

To test the fan, disconnect the yellow and use a DMM to see if you are recieving a voltage.

You could also clip this yellow wire and test the mobo. Feed a couple of volts into the mobo through the yellow wire. Take about 1k pot and connect its resistor strip between the fan red and ground. Connect the pot wiper to the yellow at the mobo. Set the pot about 1/3 of the way from ground. This SHOULD feed enough voltage to the bios sensor to fool it into believing that the fan is running. Vary the pot up and down and the bios SHOULD be fooled the into believing that the rpm of the fan is going up and down.

I should add that my specialty is electronics.... there are people on this board that know a lot more about Xp in itself then I do... but having said that, I would guess that you are seeing no problems once XP is up and running because XP does not have much to do with monitoring fan speeds and such. This is primariliy bios's job.

cheers blackbill. I'm going to look into that.

The thing I don't understand is that it only started in the last couple of months out of the blue. The same config ran without a glitch for several months before. I never installed any hardware or tampered with the BIOS.

For the time being I was able to switch off the F1 message in the bios so it boots through. But I don't feel comfortable with that, in case something really serious happens and I can't see it anymore.

thanks again
sol

P4 640, Zalman CNPS7700-Cu cooled
Asus P5GDC Deluxe
Asus nVidia 6200
Cubase, VSTi and other CPU hogs