Buzzing/Humming from bottom left side of iMac?

Optimus,
The Power supply is more to the bottom right [if you are sitting in front of the machin]...whatever you mean with humming, mine was a typical low frequency transformer sound.

If it is the CPU fan, it sounds like this:
http://scienceman.com/pgs/00_imacG5.html

The friendly guy from Apple Care told me that many callers are of the opinion that the iMac is fairly loud.

Jurgen

Your observation is correct. My Rev A I purchased last Feburary has had a slight buzz from the 1st day and does not appear to have increased in volume. It, too, comes from the bottom left and has never bothered me. It does get a bit louder whenever I play a game or perhaps use iPhoto or Imovie. Other than that I find it pretty much status quo. But if I play iTunes low I can't hear the buzz. if I step away from the computer 4 or 5 feet I would have to concentrate to hear it.

Problem is who works 5 feet away from their computer? Most people are within 1-2 feet from the screen. From here the iMac noise is irritating. It is by far the most annoying computer sound I have ever heard. It's a constant oscillating whirr when doing basic tasks like surfing the web or opening email.

Yes, it is myth that the iMac G5 is a '100% silent operator.' Neither is any other machine I can think of, unless they are turned off. The iMac g5 is, however, a quiet operator.

That aside, lower left is the location of the CPU fan. Check for dust. It could be blocking the air flow.

Could you post an iMovie recording we could listen to ourselves? iMac has built in mic that will record the machine's sound, hums included.

Good for you, Optimus

I have not only one sound but two: the fans' whirr (which is normal) and then some deep humming/vibrations.

Interestingly, when lifting the iMac off the table, it is gone...until I put it down again.

I wonder in who much the desk underneath is at fault. I may have to play around with acoustic decoupling...a simple foam mousepad won't do it.

Regards,
Jurgen

Could you post an iMovie recording we could listen to ourselves

OK, I recorded my iMac sound with the built-in mic using spin doctor. Play it in iTunes. Download link is below:

http://rapidshare.de/files/5811007/iMacG5.m4a.html

The file is 1 MB, 60 seconds long. There is music during the first few seconds which helps to convince you that there is actually something recorded. Admittedly, the sound was not too bad at the following recording conditions:

Computer was essentially idling
Uptime: almost 5 hours
Hard drive T: 45C
Smart Disk T: 51C
CPU: 50-55C

Fans at standard speeds:
CPU: 1500 rpm
Hard 2300 RPM
Syst 1700 rpm

No hum as the iMc has warmed up to operating temperature.

Maybe, you do the same...and then we can compare. I am keen on Optimus' sound.

Jurgen

If you are not familiar with Rapidshare, just grab it from my website [option-click to download]:

http://homepage.mac.com/jkraus/iMacG5.m4a/

Jurgen

I had to re-recorded my iMac sound with the built-in mic using spin doctor...because I had the microphone on default sensitivity. For this recording, I turned it fully up.

I also added recordings submitted by others. So you have now a good comparison whether all machines sound the same or different.

Play it in iTunes. Download link is below:

http://homepage.mac.com/jkraus/Macsounds.zip

My file [JK_iMacG5] is 1 MB, 62 seconds long. There is music during the first few seconds which convinces you that there is actually something recorded.

Recording conditions:
Microphone input level [Sound preferences]: full blast..note the full mic level amplifies the computer’s natural sound. It is therefore louder than real. Nevertheless, it gives you a good idea of the pitch.
Uptime: >1 hour
Hard drive T: 45C
Smart Disk T: 49C
CPU: 50-55C

Fans at standard speeds:
CPU: 1500 rpm
Hard 2300 RPM
Syst 1700 rpm

I am grateful for more submissions

My new 20" iSight iMac sounds like one of the clips in the download: BY.mp3

I has a buzzing sound coming from the lower left like a quiet mini motorbike. It goes up and down with CPU usage.

iMac arrived today. I will ring Apple tomorrow.

I am currently testing my 2nd iSight 20" G5 iMac. The first one was returned due to a buzzing noise coming from the round vent on the back. Apple support were excellent but the replacement I received (in 5 days!) is little better. Slightly less irritating but just as loud. This thing is only inches from my face and the CPU fan whirrs annoyingly: not acceptable.

Given that many others have talked about "only the sound of moving air" I am assuming I've been unlucky twice. I hope Apple will agree when I ring tomorrow.

I can definitively attest to at least one iMac G5 (iSight) - Rev C - 20" 2.1GHz with 1.5GB RAM, and it is very VERY nearly silent.

I really do have to get my ear within inches (sometimes within centimeters) of the iMac to hear anything. Really. Almost completely silent.

I typically work within about 2 to 2 and 1/2 feet of the iMac.

I did make a recording from QT and the internal mic, and from an external iSight's mic. You can hear more from the iSight recording, partially because it's situated right under the iMac, and partially because I turned the input volume to maximum for the iSight Mic (forgot to do that for the internal). Post your IM ID, and I'll iChat-it to ya - if you want to hear for yourself. The QT file is 630KB big.

I reiterate, I hear nearly nothing at all, until I get right on-top of it, even in a near-silent room with it.

Posted this somewhere else but thought it might be worth updating this thread too.

I've got iMac number three sitting in front of me and it is making a noise not unlike the first iMac they sent me a couple of weeks ago. (less annoying than the second, which was the loudest).

It is the CPU fan again. It makes an irritating purring/whirring noise. It is louder than the hard disk or blowing air noise. The pitch changes with workload.

Why? Yes I know fans make noise, although by comparison, the fan in my iMac G4 was almost silent. But how come I've had three noisy 20" iSight iMacs and other people describe identical machines which are silent or make "only the sound of moving air".

I'm not sure what to do next. I want an iMac but I can't just keep sending them back. I also don't think I can accept this level of noise. Have I been sent THREE faulty machines or three normal machines? I don't have a store nearby to answer this question.

I've had my iMac for 10 months, and am still not happy with the noise from the fans. It is especially annoying when playing DVD's, since the fan noise can be heard in quieter portions of the film. Does anyone else watch DVDs on their imac and expericence the same problem?



iMac G5 (Rev A) Mac OS X (10.4.3)