CPU Fan is Suddenly Going Full Speed? What gives!?

Two questions:

1) Is it a Dell?

2) Has the temperature in your house increased significantly in the last week?

Why would you suspect it was a Dell? I have a one, and it is almost always noisy (always was), so I was wondering why.

There could be heat problems:

Other computer fans may not be working in; power supply, or the back of the computer.

all three fans are working fine.

It was mid process in the cool of the evening...

memory joged... CPU / err.. motherboard was stressed when the keyboard 'fell' and yanked the cord..

I remedied that by replacing the non working keyboard with a wireless setup via USB.

after the keyboard disaster, the mouse port was not working either.. thank you USB!

I may re seat the heat sink and check the inner fins for dust buildup... it can cake up unseen in odd places.

For now.. I gotta go! Later.

It's the classic case of bad engineering... With all this 'clever' fan control there is just more to go wrong.
A fan going too fast isn't a problem as such it's just irritatingly noisy.
My guess is that the CPU isn't overheating...the control system just 'thinks' it is.

I have no idea where or what is in the control loop. the usual procedure for these things is...
open it up blow/suck out all the dust, waggle all the connectors....waste several weeks changing bits ...then throw it away.
Or put up with the noise.

I remember the good old days when a fan just had two wires and was on or off.

Del

Clean up the whole machine and vacuum out the USB ports to ensure good contact.

There may also be an issue with USB assignment.

hi,

Do you have any antivirus scaning softwares installed? Normally antivirus softwares make a scheduled task to scan frequently or it starts be always on at the background. That normally makes the fans to go fast to get the thermal equillibrium.

JE in Chicago,

Run windows update and check with manufacturer for BIOS update. The fan speeds are controlled by the BIOS, this type thing is common since several BIOS updates were required this past winter season.

The fan is cooling better than usual, it's not a sign for you to be concerned about.

wow!.. now my fan is spinning! .. thanks! I'll try to try all of this and reply in the next 24 or so!

You could run a CPU temperature monitor to check if the CPU really is overheating, there are plenty around to download. If it is overheating then re-attach the heatsink.

It is possible that from the shock of the keyboard fall that the heatsink was pulled loose, it is also possible that the thermistor connection that is the CPU temp sensor was damaged.

BUT, you mention that the mouse port no longer works, that makes me think that there is damage to the motherboard itself. (sheared plated through holes, cracks in the multi-layer board etc.)

My suggestion would be to seriously consider the machine as damaged and will be a long term headache. you probably might want to consider replacing the MB at a minimum.

Hi JE,

Another thing to check in addition to the links above is if the Mainboard has a fan sensor. Many computer mainboard mfg like ASUS now have a cpu fan control circuit on the mainboard to regulate and vary fan speed based on cpu internal temperature. If this sensor goes bad it could cause the kind of problem you are describing, check with the mainboard mfg for specific information about the board in your PC.

In your initial statement, I read "It's not dust buildup on a thermo..". I took that as you have done a complete internal inspection to ensure there is no dust/dirt build-up. I also experienced this problem (especially during anti-virus scan), and decided one day to open her up. Found a lot of cat hair (thank you, FatKat), dust, etc. Once cleaned out, no more overspeed fan exercises.

Hope it helps.

MD

Run! Run! Get away before she blows!

ive got a good computer its a Tusunmi comp for cooling ive got a high proformace intercooler it works has huge airvents in the frount and rearat the moment my comp is running very cold then again its set up for gaming and the internet i find no problem with useing a intercooler the comp has the same cooling as the rest of the ships computers

My Gateway FX530XG computer's fans suddenly increased to full speed. Normally they only run that fast for a few seconds at startup. I did fix it. Here is how. Please try just doing a "System Restore" back to before the speed up happened. (The fans were still fast after that restoration). Then shut down the computer (start>turn off). Then unplug the computer from the 120 V source, and leave unplugged for a few hours. After I plugged the power back in, and turned the computer on, the fans were normal again.

The fan problem happened after a blank 'ready to send' Email pop-up appeared. I was afraid to click anywhere on it. (I never use email on this computer). I tried to turn the computer off normally, but there was no response to the mouse clicks. At the same time there were "automatic windows updates" waiting to be installed, but the computer would not respond to that either. Finally, in desperation, I pushed and held in the on/off button for about 5 seconds.

After I turned the computer on again, the email pop-up was gone, but the fans kept running at full speed-loud!! I ran a virus scan, nothing found. I restored to an earlier time, still full speed fans. I checked the BIOS, (F2 at startup) and saw nothing suggesting some fan speed control. My best guess is that the holding in of the on/off button combined with that pop-up and/or windows update somehow caused the fan speed control to lock at full speed. To reset the fan speed control, the computer actually had to be physically disconnected from the 120 V supply. My time unplugged was 2 hours.

In reading these type of blogs, the suggestion was made about unplugging from the 120 V supply. That worked. Thanks much to all of you kind posters who share their experiences.

It finally got its Second Wind? Mine took three years. Out of shape, I suppose.