CPU fan seems to run all the time?

[Orrex]

We have an older Dell desktop that has served us well for four years and continues to do so, but in recent months the CPU fan appears to run almost nonstop. What might have changed to cause this? Is it a problem?

I've wondered if it's in part a problem of the ambient temperature, since it's summer and all that, but it didn't do this last year, and in any case it started during the last months of winter.

At least, I think it's the CPU fan. Certainly sounds like a fan, and I've confirmed that it's not the DVD player.

Helpful suggestions are greatly appreciated. Thanks!

[HereSince1628]

1. I had similar problems 2 years ago...

Keeping anti-virus and malware up to date and running them regularly seems to help.

Here's what I said back then...

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=317x3967

[Orrex]

2. The problem might actually be that I'm a dumbass

If only I had some means of delivering a blast of air in a concentrated stream with which I might, for instance, blow the dust out of the fan and heat sink.

I took the side panel off and hit it with the air, and now it seems to run whisper-quiet.


Can't believe I didn't think to try that. What a dumbass!

[Mnpaul]

3. Make sure to get all the dust out

Sometimes you have to remove the fan from the heatsink. On some Dells, it just snaps off with the release of a few clips. Its a good idea to clear out as much as you can with a vacuum first and don't spin the fan with compressed air. It can damage the fan. It may be fun but it is not good for the fan. An old toothbrush comes in handy here as well.

A lot of dust can be hiding under that fan


It is a good idea to clean the inside of your pc at least once a year.

[Orrex]

4. Thanks for the tip--I'll give it a shot

It's whisper-quiet now, but there's no harm in making extra sure!

[wandy]

6. While you're at it. If you can determin the fan size, rotation and speed........

Go out to Newegg or someone like that and order a new good quality fan.
I doubt it would be more than 10 bucks and the peace of mind is well worth it.

In addition to dust consider the possablity that the current fan bearing might have degenerted causing the fan to run slow.
This also may be why you hear the CPU fan.
If you are new to this type of 'surgery' , and have gotten this far, it's like I said, the 10 bucks is worth it for peace of mind if nothing else.

[Go Vols]

5. .

Mine runs 24/7 and I take it apart yearly to clean dust.Usually happens when I hear the fan running more than it should.

[grok]

7. thermal compound paste might have gone bad

If your fan is reasonably clean and working(obviously it is) the thermal heatsink compound just might not be doing it's job. It is a thin layer of paste between your actual CPU and the heatsink/fan assembly. Theoretically you shouldn't need it but it compensates for the (real-world)imperfect mating for the surfaces of the cpu and the cooling assembly.

If it cracks or dries out it could be failing to efficiently transfer the heat away from the cpu to the heatsink. might actually make the situation worse by separating surfaces further) The thermal sensor on the cpu/motherboard sees this and turns on the fan full blast to compensate.

The procedure is to disconnect power, remove the heatsink/fan. Carefully clean both surfaces(alcohol swab) apply fresh THIN coat of thermal paste) and re-install. Don't be nasty about it.

I recommend Arctic Silver Paste which you can find at any radio shack. you could probably use the cheap stuff too.

There are several youtube/google examples of how to do it online..

[HopeHoops]

8. That's not unusual. Try vacuuming the motherboard with the brush attachment.

Dust is a MAJOR enemy. The CPU fan is your front-line defense. It WILL run constantly if the CPU is overheating and they do get hotter with age. Try to keep the insides as clean as possible. That helps. If the fan STOPS running, then you have a reason to worry.