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davidmmac
28-01-2009, 09:13 AM
Booted up my desktop computer this morning, went away for a about 5 minutes, came back, and it was making a loud whirring sound. Usually when it does anything like this it comes from the dvd drive, so I ejected it, but to no avail. Decided to reboot, but again, after about 3 minutes, a fan started up and it was making a racket, so I just turned it off. It sounds like it's coming from the back end of the computer.

Any ideas?

:confused::confused::confused:

wainuitech
28-01-2009, 09:19 AM
Only two things that spin in a PC - the Hard drives disk and cooling fans.

Its will be one of the fans, prob full of dirt, dust etc.

Take the side off the case, turn on the PC and generally you can tell which fan is making the noise. locate the right fan and replace it. No real point in cleaning them, as crap gets in and acts like grinding paste - cleaning may quieten it for a while, but it will return again.

It could also be the cooling fan in the PSU but more often than not its the rear case fan or CPU Fan.

joshjnz
28-01-2009, 10:04 AM
Just cleaned out my computer with some compressed air and it's made a huge difference. It's much quieter.

davidmmac
28-01-2009, 02:51 PM
Thanks Wainiutech :thanks

That seems to have stopped it. I didn't track down the source of the sound, but I gave the back fan a clean and all now seems well. It's a bit rusty around that fan, is that normal?

feersumendjinn
28-01-2009, 06:34 PM
No, rust is not normal, sounds like you're drawing damp air through the computer (is it near a window, or the bathroom or kitchen?).
The fan noise will come back, a good way to find the noise is to use a piece of hose (garden hose is good) as a stethoscope, one end in your ear/wave the other end near your fans to localise the noise.

davidmmac
28-01-2009, 09:06 PM
No, rust is not normal, sounds like you're drawing damp air through the computer (is it near a window, or the bathroom or kitchen?).
The fan noise will come back, a good way to find the noise is to use a piece of hose (garden hose is good) as a stethoscope, one end in your ear/wave the other end near your fans to localise the noise.

Thanks for the advice about the fans.

I purchased the computer off Trade Me and it came with the rust, is it bad to have rust? Should I consider buying a new case?

feersumendjinn
28-01-2009, 10:41 PM
If the rust was pre-existent, I wouldn't worry too much now if it's running OK (it may have caused corrosion on the motherboard slots/plugs/sockets etc, through condensation (being bare metal)).

dugimodo
29-01-2009, 04:58 PM
the fan may be fine, a lot of computers get noisy in summer due to dust buildup in combination with the hotter days causing the system to crank up the fan speed to compensate. Cleaning the dust out will cool things down and allow the fan to slow down.

It's not hard with practice to hear the difference between a loud fan and one with problems ( i.e. worn bearings / bush whatever )

davidmmac
29-03-2009, 06:55 PM
You guys were right, the sound has come back.

First it was last night, then this morning, now this afternoon.

But the good news is I've diagnosed that it's coming from the back case fan, so I decided to look for a replacement, only, I have no idea what size to look for. All of the ones I've found are either 8 or 12 cm, but where is it measured from?

Blam
29-03-2009, 08:57 PM
You just measure the diameter.

Get the Antec Tricool or one of the SycthX ones

wainuitech
29-03-2009, 09:21 PM
Case Fans are measured by the actual physical OUTSIDE dimensions of the Fan housing, not the blade dia.

To see what you currently have either remove it ( or if able to get a small tape measure/ruler in the case) and measure from side to side, it will either be 80mm, 90mm or 120mm.

If you also look at th rear of the case there should be four screws holding it in, you can tell ( from experience just by looking) but if un sure , measure the screw centers. ( as also shown in attached pic)

Case fan Sizes across the screw holes: (1st number is fan size)


80mm = 72mm
90mm = 82mm
120mm = 105mm



Edited:

Sometimes you can also put in bigger fans than are already there - less noise - if you look at the attached Pic, you will see by the inside arrows, it has a 80mm fan, but the mounting holes are there as indicated by the outside arrows to take a 90mm fan.

davidmmac
03-04-2009, 06:38 PM
Thanks for the info guys.

Fan is a 80mm, so I will buy a replacement soon. In the meantime, is it safe to just to leave the side panel off and disconnect the rear case fan?

Blam
03-04-2009, 07:12 PM
Depends on your current fan setup. Will probably be fine(ran a system without any case fans once!), but keep an eye on the temps.

Blam

wainuitech
03-04-2009, 07:43 PM
Case sides what are they :confused: :lol:

The workshop PC's only have the rear side on, usually no rear fan, only the CPU and maybe the Graphic card if it has one - the left side ( looking at the front) never has a cover on - cant attach HDD's and test with sides, and it would be a pain to have to remove them each time I wanted to test/clean a customers drive. Typical setup (http://www.imagef1.net.nz/files/Typical.JPG)

The PC's in the house are all fully assembled.

davidmmac
03-04-2009, 08:10 PM
Thanks, I'll give it a go and I'll monitor the temperature :)