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I have a PC that displays the message "fan not working". Why is this message being displayed when the fan is working?

GALVIS asked
Nothing has been attempted thus far.
Watch Question

IT Consultant
if you are sure that fan is working then only reason I can see is that sensor monitoring fan (on motherboard) is not working properly or broken
is this message displayed when you are starting PC or directly in Windows enviroment?
if this message is generated by some 3th party software it could be also problem of this SW (compatibility) and you can check SW provider update maybe
Most Valuable Expert 2015

Check the BIOS settings and the fans actually installed. There are often extra fans for the case etc., and in many BIOS's you can enable those fans for monitoring too. If you have enabled such a fan in the BIOS that isn't even connected, you will get this type of error.
EirmanChief Operations Manager

You can have many fans on a PC.

=) Most CPUs have one (although there may be only a big heat sink / watercooling)
=) At least one of these: Front fan, Side fan, Rear fan

=) There is also a rear fan on the back for the power supply
     but that wouldn't cause your present warning.
Harper McDonaldSr. Cloud Support Engineer

Flash your BIOS to the most recent version.
Danny ChildIT Manager

The fans may be spinning, but may be too slow for adequate cooling.

You may want to clean the fans that are there now, with an air spray duster.

If the fault recurs, you could exchange any of the fans for a known good one, or look into SpeedFan for more monitoring:
Danny ChildIT Manager

It also could be an intermittent problem, where a fan stopped working on boot, but gradually got up to speed.  If so, I'd recommend monitoring the PC over time to see if it gets more frequent, and to perhaps make sure you have a spare in stock.
Most HP's will display this message and some won't even boot afterwards!  What is the make and model of the PC?
Top Expert 2013

a bit more info :
the fan - usually the CPU fan has 3 wires : 2 for power, and one for sensing
the motherboard has a sensing, or even control device for the fan
usually in the bios you can see the fan speed - if it is too low - it errors out
that's what the guys above were telling you
if you have another fan around - replacing it is a good test
if the motherboard sensor is bad - it won't help; you need then to disable this in the bios, or replace the board


This solution drew my attention to the fan sensor wire as I knew that the fan was working fine.


The fan not working message was appearing upon startup. The affected user will be getting a new PC soon so as a result will not be pursuing a fix at this moment in time. The user is currently getting round the message by pressing F1 each time.


Many thanks to all the experts for their helpful suggestions.