Noisy Fan

[andyk]

Hi

 

We have a computer in the office which makes a very loud noise when we switch it on. I have a feeling that it may be the PSU fan as when I push slightly on the back of the pc, around the power pack, the noise reduces.

 

I have cleaned out all of the computer inside as there was a lot of dust, but I was just wondering if anyone could give me some tips on identifying whether this would be a PSU fan issue or the fan over the CPU etc.

 

Any advice appreciated.

 

Regards

Andy

[elsiegee40]

What make of computer is it? How old? Does the fan quieten after a short time?

[synaesthesia]

Pop it open and look.

Are any cables rubbing against the fan? If so, move.

If not, stop each fan in turn, very shortly, with your finger or an eraser if you're H&S minded or clumsy like me. (in the middle, not the blades ). If noise ceases, you've found the fan. Replace or repair (sewing machine oil under the label/seal in the center spindle). If it's power supply, only try repairing if you're desperate and don't have a spare power supply.

 

Many of our RM F series machines make one HELL of a racket in the mornings when first turned on but it goes after a minute or so. Thank goodness for wake on lan!

 

PS: may want to move this to the hardware forum.

[andyk]

Hi Guys thanks for your replies.

 

Synaesthesia, thanks for the tips, will have a look tomorrow when I am in. After posting I wanted to move to the hardware thread but can't figure out how!

 

elsiegee40, not sure of the make off hand, but it is very old - cream in colour!

[elsiegee40]

The reason I asked for the make is because some can be worse at this than others. As synaesthesia says some sound like they're trying to take off when they first start and then settle down. I have an HP server that sounds like it's doing a moon launch when I reboot it! The dust it blows around is unbelievable (I do try to remember to get the vac out before I reboot it!)

 

It can also be an ageing fan that is on it's way out... or simply one where the bearings are starting to go. A little sewing machine oil can help, but if it settles down quite quickly I wouldn't worry too much.

Edited October 16, 2012 by elsiegee40

[twin--turbo]

It may just be resonance and may require a bit of padding on the case or components to sort.

 

Rob

[andyk]

Thanks Rob, will give that a try.

 

Regards

Andrew

[pcstru]

Just a note of caution. Please treat power supplies with respect. If the fan that is noisy is in the power supply, replace the supply in preference to opening up the power supply and ... 'playing with' with the fan/s. Switched mode power supplies can be very, very nasty even when powered off.

[elsiegee40]

Just a note of caution. Please treat power supplies with respect. If the fan that is noisy is in the power supply' date=' replace the supply in preference to opening up the power supply and ... 'playing with' with the fan/s. Switched mode power supplies can be very, very nasty even when powered off.[/quote']

 

Agreed

[synaesthesia]

^ very true. I do it often, but only because I'm masochistic and think nothing of the jolt those things can give off. They can kill.

[difinity]

A mechanics stethoscope, bought from ebay for less than a fiver is an easy way of diagnosing noisy fans.

[synaesthesia]

?? Nothing like over-complicating things for the sake of a £hardlyany plastic fan!

[Vine]

If your CPU has a Heat Sink with a fan attachment (Like nearly all HP Desktops) then you may find that it's overheating. The fan will sound like it's taking off!

 

You could:

 

Check the BIOS' CPU Temperature (If applicable)

Re-seat the Heatsink

Check that there is enough Thermal Coolant/Paste. If so, clean the original Thermal Coolant with some Isopropanol/Isopropyl Alchohol (Check brand names like Iso-clene or try rubbing alchohol) Use caution with this as it's really irritant and with make bare skin feel very 'dry'. Apply the right amount of thermal paste when the old paste is gone and the CPU (Again use caution, don't damage the pins!) and the heatsink are both dry of Isopropnanananalalapyl .

Maybe check that the fan functions in a similar model and doesn't sound noisy, isolating the machine the fan originated from.

 

There is a whole HOST of things you can try!

 

Viney.

[craigt]

Adding onto other people's comments. try using a can of compressed air while holding the fan to give it a blast to clear out any dust etc