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wolfen · Oct 1, 2007, 02:37 PM

So I have a 2.4/24" that I bought the day after they came out. It has been silent from day one. When I say silent, I mean as quiet as any LCD panel. Silent.

Today there's a low frequency hum that you can hear if you're 1-2 feet from the machine. And if you touch it you can feel a slight vibration. This vibration is strongest in the bottom left quarter of the machine as you look at it from the front. Along with the hum and vibration, there's a very very slight fan-like noise. Temp monitors all come up within very safe and normal ranges.

So I'm thinking maybe, perhaps, the disk drive is acting up. Dunno what else it can be. The only thing I changed was in the previous 48 hours I moved the iMac from one room to another, and then back to the original room. But it was done gently and without any jarring. So I dunno. Just thought I'd throw this out there...

.Neo · Oct 1, 2007, 03:33 PM

My iMac vibrates slightly as well when touching it. I got the 2.8 GHz 24-inch one. And the one I got before that (which I returned because it had a damaged glass plate) did it as well.

ripdog · Oct 2, 2007, 02:50 AM

The humming is probably the CPU or GPU fan running, the machine might be silent when cold, but high load or heat will cause the fans to start up, causing vibration and noise. This is normal.

In fact, i would be more worried if there was no noise or vibration, its only a problem if the vibration is erratic or excessively violent.

.Neo · Oct 2, 2007, 11:49 AM

The vibrating is pretty stable here. No weird drops or highs in intensity.

Veltliner · Oct 2, 2007, 02:24 PM

Wolfen, you said your machine was silent at the beginning.

So maybe you just contact apple again, until they get it right. After all, one of the advantages of an iMac is, that it's a silent computer (I don't think this has changed with the aluminum ones).

If it disturbs you - and it would definitely disturb me - take it back to apple, and let them have a look.

Mike Pither · Oct 3, 2007, 12:01 PM

mine does it to after an hour or so of use. If I squeeze the ally frame and back together it will stop. At least on mine it seems that the plastic back is vibrating / resonating once the machine is warmed up. It's very faint and I can only here it if the room is completely silent fortunately.

Veltliner · Oct 3, 2007, 12:09 PM

Originally Posted by Mike Pither

mine does it to after an hour or so of use. If I squeeze the ally frame and back together it will stop.

So maybe it just needs a hug

.

Seriously, iMacs have gone more silent over time, and now this repeatedly reported noise issue. I guess that's because it is the first generation. First generation models often have slight issues, that disappear with the refinement that happens with model updates.

HAGEhead · Oct 3, 2007, 02:02 PM

This sounds like just an initial manufacturing issue, the iMac in itself is still one of the quietest mainstream computers available.

mix123 · Oct 5, 2007, 01:33 AM

I was thinking the same thing about my imac the other day....that it got louder. But it's so hard to tell lol. I mean I can hear a fan running very faintly and the hd when it's working. But I can't remember if the slight fan sound was there before or not. Too hard to tell. Oh well seems pretty quiet to me. Are these fan speeds correct: at startup -

Optical drive : 698 rpm
CPU fan : 1200 rpm
HD fan : 1199 rpm

wolfen · Oct 6, 2007, 05:00 PM

I should probably clarify a couple of things.

First, our home is a steady 74 degrees no matter what. So ambient temp would not seem to be the problem.

Second, it's only noticeable when there is absolutely no noise at all. To give an example of how picky I am, we spent several thousand dollars on a fridge because it is a very silent model. My home is intentionally dead quiet unless it's a hot day and the AC is the only thing to be heard. So those are the conditions under which I hear this hum. But right now with my AC running and my wife playing WoW beside me, you'd never know.

So now you know that when I say it was dead silent for its first month or so, it really was. But I wouldn't consider this new noise an issue that 99% of people would ever detect.

experimental · Oct 6, 2007, 09:18 PM

Its quite normal for an internal fan to pick up a little dust over time. This is quite usual. The very first G5 iMac were famous for this (amongst other things!) and pics soon surfaced on the web. Apple could do nothing about this except release a better design.
I think you have one of the better releases for sure. Enjoy.