Error for fan failure but the fan did not fail

[kerryhills]

"ERROR: CPU Fan Has Failed! PC will automatically power down in a few seconds. Service the PC immediately to prevent damage to the PC."

I did look in the knowledge base and there was nothing useful.  I did try to get to the bios but the error message always came up and shut it down even when I could see the initial bios screen for a split second. 

*Relevant Facts*:

The fan has not failed

When the computer is powered on the heat-sink fan and the case fan both start up, then the go off and the error message appears.  This happens within a couple of seconds.

I even tried a new replacement fan, same error message.

Like others I cannot get to the bios (using F8, which is the proper command)

I have not changed hardware

I have not upgraded the bios

It is running Windows 7 Pro

I did try F2 and it started to boot but the fans did not come on and I shut it down since I could feel heat building in the heat-sink.

Any ideas would be great, this is a great machine and I'm hopeful I can keep it going.

Thanks!

The AMD processor has a heat sink

About 18 months ago I replace the computer fan with a quieter Noctua fan, the NF-A8.

[WAWood · Accepted solution]

@kerryhills 

Sorry, but I don't have good news for you.

I have run into this same issue on older HP MediaCenter PCs -- and in all cases, the following was true:

1) Fan was working anyway

2) PC fan ran fast initially, then slowed down, but continued to run

3) PCs did NOT overheat

4) Went into BIOS, found the setting to monitor the fan, disabled it -- message disappeared

If your PC is shutting down, then it really is a fan issue, and since that is powered and controlled by the motherboard, that implies a circuit fault in the motherboard -- which you are NOT going to be able to fix.

A POSSIBLE workaround (if you want to attempt this) is to purchase and adapter that will allow you to connect the 3or 4-pin fan lead directly to a power lead from the PSU.  That way, the fan will run, the motherboard will not monitor it, and you PC will then NOT shut down.  The downside is that the fan will then run at a constant speed -- because the motherboard will no longer be controlling it.

However, with the fan connected like this, your PC might shut down anyway -- since it will no longer "see" the fan.