Buzzing Noise From Bottom of iMac

send it back to apple if you are not comfortable with the noise...
😉

SalD,
If is was the HD, the sound would be a bit metallic and rather unsteady. For fan sound see

http://scienceman.com/pgs/00_imacG5.html

Jurgen,

Excellent link to that Science Man site, and I can now confirm that, point C, that pesky air fan in the bottom left is the culprit.

Now how to fix it? Are Apple replacing these units knowing that when taxed up on a chore, these iMacs are a real pain! Unless you crank up iTunes!

🙂

I had the same buzzing noise from my mac too. When I reduced the screen brightness the 'electrical buzzing' decreased in volume, and when I increased the brightness, the buzzing got louder.

It turned out to be a dodgy power supply. The power socket at the back of the machine was a little loose. Fortunately I had 12 months warranty on the machine so I got a new power supply fitted.

Runs like a dream now, dead quiet!

Right. This is the way to confirm whether or not the power supply is the problem. It seems as though the screen-buzz can easily be fixed by replacing the PSU. Unfortunately, if dimming the screen does not reduce the buzz, then the fan is the culprit and the solution is much more tricky.

I wonder how much money they've lost by sending out PSUs and midplanes willy-nilly instead of redesigning a $5 fan and sending it out to the many unhappy customers?

Hi john - I noticed that the entire "imac buzzing" thread you started has disappeared! I find this rather strange as it contained probably the most useful information for users regarding the very common buzzing problem (about 90 posts IIRC).

Anyway, if you'd like to keep in contact visit www.geometric.co.nz and click on the logo, you can email me there. Hope things are going well for you.

Right Anthony, I'll speak with you via email.

Anybody else who is looking for a fix to the buzzing CPU fan on the 17" iMac, we may have found a solution. More info later!

Yes please, keep us in the loop!

Please, we NEED a fix!!!!!!!!!!!!!

Mircubit,
Sorry for the delay. Only Apple can fix it...by giving you a new fan. Contact them.
Jurgen

Here's something to look at. It's long and in depth but I think it's a good summary of my research into this problem.

http://www.geocities.com/uofr06/imacproject/

Fortunately I had downloaded the discussion at 22/8 in DEVONthink. BTW a page with info on Fan Replacement, on a Mac.com addres, has also disappeared. Compared to some non-Apple lists, the tone was definitely not offensive (which is a good thing, I think).

Removing a whole thread is brutal on Apple's part. I have once seen a single post being removed at NoteBook's mail forum since it contained expletives. Apple should do the same, if they do not want to create the impression that they remove material which is true, but unflattering for their products.

And I remember this is not the first time that a thread was removed, that's why I made a copy in the first place.

Meanwhile I've discovered that my CPU when relatively quiet is at 3500 rpm, when noisy at 5600 rpm. As an aside, the noise has been louder at times, so I wonder whether there is a direct link between rpm and noise.

This is for a iMac G5 rev. a 17".

Smolk:

Does your CPU fan, normally, goes up to 5600? What is the normal rpm?
I never though any of the fans revved that high under any circumstances.

smolk-

Are you saying that you downloaded the "iMac Buzzing" discussion (90+ posts) that was removed?

If so, anyway I could get a copy of it? I'd love to post it on my iMac Project site...

Idle speeds on my iMac are:

CPU: 1500
Hard Drive: 2500
System: 2000

I've rarely seen my CPU fan go above 1900...