'CPU fan error' upon boot-up

[ghoti]

I'd sure appreciate some help!

I am running a socket 940 FX-53 and an ASUS SK8V. 'Everest' told me (under 'Sensor') that the CPU was running at an idling temp of about 48 degrees C., and 60C. under load (Baldur's Gate/ Sword Coast). I decided this was too hot, and went for a Thermalright XP-90 with a 92mm Panaflo fan, and Arctic Silver.

Now, Everest tells me that the idling and load temps are roughly 10 degrees (Celsius) cooler. That's great!, BUT:

Now, whenever I boot up, I get a BIOS ('American Megatrends') error message: 'CPU fan error, press F1 to continue'. I press F1 and the machine boots up fine. (I never got this error message before installing the new heat sink and fan.) AND, Everest, which used to report the case fan RPM (as well as the CPU fan RPM) now reports ONLY the CPU fan RPM. It will no longer show me the case fan RPM.

I've checked the connections (three conductor plug to the CPU fan, and the three conductor CPU fan plug to the motherboard), and both are tight.

Any help please?

Thanks much!

 

[theMan]

go into the bios, and it will say hardware monitor somewhere, not quite sure where it is. it will have your fan speed. if it shows a speed, but it is red, dont worry about it. that just means the fan is spinning slower than the bios wants. press enter, and select ignore. if there is no speed shown, but you know the fan is spinning, it must be connected incorrectly.

 

[ghoti]

Thanks Compy!

I checked BIOS and found that the CPU fan listing says 'N/A', while the 'chassis fan' [what's that? - I have two 120 mm case fans in this Antec SLK 3700 AMB] shows 2235 rpm, which is the number Everest reports as the CPU fan speed.

So what could be the problem with the connection for the CPU fan? Bad fan pin? bad connecting wire?

Any further thoughts?

 

[FlyingPenguin]

Sounds like you plugged the CPU fan into the chassis fan socket. The chassis fan is the optional intake fan on the front of the case.

Additionally RPM sensor electronics on some mobos don't work properly with some fans - especially fans that have built-in thermal sensors and change speeds automatically.

 

[ghoti]

Thanks.

I double checked, and the plug is plugged into the socket on the MB labeled 'CPU' -- the same socket I was plugged into with the prior fan (on the original CPU heat sink), which worked just fine as far as Everest reporting CPU fan speed.

Sure am puzzled!

 

[Bozo Galora]

the panaflo isnt variable, is it?

 

[ghoti]

There is a screw-driver adjustable control on a pair of wires running not to the fan, but to either the power supply or the MB (I cannot recall which, and I cannot find mention of it in the literature for either the Antec True Power 480 or the MB). In any case, it is turned all the way up and was the same before I changed out the stock heat sink & fan, which seemed to work just fine (at least insofar as reporting under Everest, and no error report on BIOS boot-up).

Thanks!

 

[Oyeve]

As long as the fan works and your system is cooler I wouldnt worry about it. Just disable the reporting in Bios and in what ever SW you use to monitor it.

 

[ghoti]

Thanks for the suggestion. I'm a bit leary though about disabling the BIOS error reporting for the CPU fan; what happens when and if it really does quit? I'd like to figure out what's wrong, and get it working agin.

 

[Oyeve]

Originally posted by: ghoti
Thanks for the suggestion. I'm a bit leary though about disabling the BIOS error reporting for the CPU fan; what happens when and if it really does quit? I'd like to figure out what's wrong, and get it working agin.

Even if it it failed, I doubt your CPU would last long enough to report it. You would most likely hear a sudden quiet emminating from your system which means the fan went.

 

[Buz2b]

Originally posted by: ghoti
I'd sure appreciate some help!

I am running a socket 940 FX-53 and an ASUS SK8V. 'Everest' told me (under 'Sensor') that the CPU was running at an idling temp of about 48 degrees C., and 60C. under load (Baldur's Gate/ Sword Coast). I decided this was too hot, and went for a Thermalright XP-90 with a 92mm Panaflo fan, and Arctic Silver.

Now, Everest tells me that the idling and load temps are roughly 10 degrees (Celsius) cooler. That's great!, BUT:

Now, whenever I boot up, I get a BIOS ('American Megatrends') error message: 'CPU fan error, press F1 to continue'. I press F1 and the machine boots up fine. (I never got this error message before installing the new heat sink and fan.) AND, Everest, which used to report the case fan RPM (as well as the CPU fan RPM) now reports ONLY the CPU fan RPM. It will no longer show me the case fan RPM.

I've checked the connections (three conductor plug to the CPU fan, and the three conductor CPU fan plug to the motherboard), and both are tight.

Any help please?

Thanks much!

You might have the plug going into the fan reversed. If you don't have another system to try this on, then don't do it but I would remove the CPU fan and then unplug the "three conductor plug to the CPU fan" and reverse it. Then plug it into the chassis fan plug on a different MB and make sure it works OK. If so, reinstall it to the original system and see if it reports the correct rpms.
Another suggestion would be to plug the CPU fan into the "chassis fan" port and plug a different fan into the CPU port. Then see what they report. If the CPU fan still has problems reporting then you know it is the fan and not the MB. At that point, see suggestion #1 or get a new fan. BTW, I'm not sure if the fan would even work if the wires were reversed but it's worth a shot. Make sure you have a replacement fan before doing this though. J/K

 

[ghoti]

Well, I figured out the problem -- it seems the Panaflo M1A does NOT have an RPM sensor, so the software (including the BIOS) could not detect the CPU fan RPM, resulting in the BIOS-reported 'CPU fan error'.

I went back and bought the Panaflo H1A (w/ RPM sensor) for a dollar more than I'd paid for the M1A, and all works fine now. Too bad I had to learn the hard way (by the time I finish paying shipping back, it's not worth returning the first fan, and I also had to pay the shipping to me for the second fan). It would have been nice if the people I bought from had alerted me to first fan's lack of any RPM sensor.

Thanks all for taking the time to offer suggestions!

 

[Buz2b]

Originally posted by: ghoti
Well, I figured out the problem -- it seems the Panaflo M1A does NOT have an RPM sensor, so the software (including the BIOS) could not detect the CPU fan RPM, resulting in the BIOS-reported 'CPU fan error'.

I went back and bought the Panaflo H1A (w/ RPM sensor) for a dollar more than I'd paid for the M1A, and all works fine now. Too bad I had to learn the hard way (by the time I finish paying shipping back, it's not worth returning the first fan, and I also had to pay the shipping to me for the second fan). It would have been nice if the people I bought from had alerted me to first fan's lack of any RPM sensor.

Thanks all for taking the time to offer suggestions!

Oops! Glad you got it figured out, although it cost a few bucks. But look on the brighter side, it could have been the MB and that would have been a lot more expensive. As far as the vendor not telling you it had an rpm sensor wire, they really don't know how a fan is going to be used when you buy it. Many use the panaflos for case fans and seldom have the need for rpm monitoring because of their low speed/noise ratio. Looking around, some sites do mention no rpm sensor and some do not. Anyway, a fairly inexpensive "fix" in the end. Be happy for that! Good luck!

 

[Zepper]

In Panaflo, the fan name tells the tale. Those ending in A (L1A, M1A) do NOT have the fan speed sensor wire - those ending in BX (L1BX, M1BX) do have the fan sensor. Few Panaflo fans that make it to the states have the sensor but many will still have the 3-wire leads - the unscrupulous take advantage of this. Their listings will say "3-wire" but never mention the speed sensor thus allowing you to "assume"... So you must be careful when buying Panaflos.

.bh.