View Full Version : Roaring on & off Fan, is it serious??

03-01-2010, 02:48 PM
Over last 2 days one of the fans starts roaring for about 20 sec then stops. (I think itís a fan).
Comp has 3, bottom one is a bit noisy and compt tech said I could replace it with a bigger heat sink and no fan, but this is definitely at the top of the tower, somewhere near the power supply? that was replaced months ago.
I saw a thread and thought maybe it was something to do with a drive.
But mine is not on start up, just during day when using it.
Plus I donít know where to find BIOS. Is it serious??
Vista, Explore 7

03-01-2010, 05:05 PM
Take the side off and take a look, get a pencil, and GENTLY place it against the middle of the fan to stop it temporarily (like a second or two), that will tell you which is the noisy one if you can't tell by ear.

If its a case fan, you can replace it - the bearings fail in them sometimes.

If CPU or GPU fan, panic now.

If PSU, well, not quite so bad but i'd see about replacing that too, you can, if you have enough skill, replace the fan only in a PSU.

03-01-2010, 06:19 PM
My laptop CPU fans (yes I have 2) are pretty noisy when it goes at top speed, nothing wrong with it at all - but that's what you get when Toshiba sticks a 3.33Ghz P4 Prescott in a laptop... :lol:

In your case it could be that the fan is old, jammed and in response to a high increase in temperature (due to it not actually spinning at all on the lower speed) the controller is hitting it with full voltage, causing it to run at full blast, which could be rather noisy.

It's not easy to figure out what to do about it until you figure out why it's doing it.

03-01-2010, 06:46 PM
Or maybe it's filthy and full of fluff...........

03-01-2010, 06:48 PM
Now got down level with back, and even though bit blows out of top vent I've realised its next vent down. According to HP diagram is the case fan. But theres no big vent for GPU fan (just little holes in case side), which is on the side. So wondering if the GPU fan would blow through the middle vent as well. If not it will be just case fan.

Also how would updating BIOS stop a fan being noisy
Near bottom of article for processor and case fan

1) So whats best make of case fan
2) need to replace Graphics ?? fan withbetter heat sink unit, & no fan, Good make??

NB comp 2 years old Hp pavillion media centre m8070a

03-01-2010, 06:51 PM
The BIOS controls the Fan speed. Updating the BIOS may change the code that controls the fans, causing them to normally run slower or start up at a higher temperature

03-01-2010, 06:54 PM
Many fans will respond well to simple cleaning of the airway and impeller and a re-lubrication of the bearings. I usually find that they last longer after a re-lub. than they did from new.

03-01-2010, 07:34 PM
Thans for info about BIOS
Will open up in day or 2 when shops open.
It was cleaned a bit in Sept, but house gets dusty quickly so could be that .

04-01-2010, 12:40 AM
Case service info and other manuals here
and here
The case fan (below the PSU, on the back of the case) looks like a standard 80mm unit, just buy and fit a new one.
A good way to isolate the noise is to get a piece of hose 500mm(ish) long (garden hose diameter is good), hold one end to your ear and hold the other end close to the noise source (acts like a stethoscope :p ).