iMac 27" buzzing/hum

[TennisandMusic]

Anyone with a 27 inch iMac ever hear a faint buzzing or low hum from time to time from the machine? Not sure how else to describe it, it's pretty quiet, but apparent enough to annoy perhaps. Makes it sound more like a home appliance. Anyone? Is this normal for iMac's or would this, yet again, be a cause for switching one out?

[Davieis]

Does the volume of the buzz increase/decrease when changing the brightness?

[duky]

I'm having this issue when on low brightness. Did either of you solve the problem? When the computer display goes to sleep, or when it dims after some time, the buzzing begins. Any ideas? Solutions? Probably going to have to call Apple support tomorrow morning

[TennisandMusic]

I'm having this issue when on low brightness. Did either of you solve the problem? When the computer display goes to sleep, or when it dims after some time, the buzzing begins. Any ideas? Solutions? Probably going to have to call Apple support tomorrow morning

After two faulty machines, took mine back for a refund.

[duky]

Yikes, well I'll speak to support and see if anything comes of it. I'll probably give up pretty easily because it's not that major of an issue though it is annoying when I come home from work to a silent room and hear that humming.

[mtnDewFTW]

I had that on my original iMac. Then I called AppleCare and got a new one. I wouldn't say that it's completely quiet now, but not as loud. It might be the fans pushing air.

[mil098]

Yes I got the same buzzing noise.

Sounds electrical, coming from the top rear of the unit.

I rang Apple and they have DOA'ed my machine. (1 day old)

Also I found that my machine would go back to full brightness after either a reboot or a full power down.

SMC reset, PRAM reset the whole lot has been done, Apple support could not work it out.

[swee5420]

I have this issue in all replacement

[duky]

Looks like I'll just have to live with it. Quite annoying though but I'm hoping I just get over it.