09-18-2010, 02:20 PM

Hello all

I just got a new 2.8 quad core imac, 27". Its great although i feel the fans are noisy. Its constant whirring, like one of the fan blades is clipping on something. It doesnt sound like a HDD noise and its from the moment it turns on to the moment i turn it off, always constant, never differs.
I installed smc and get these readings -

OD - 1000rpm
HDD - 1099rpm
CPU - 939rpm

These, i think, are pretty normal. Any ideas? Tried an SMC reset and resetting the PRAM (which sorted it for a few seconds, then back to normal...) to no avail. It sounds like the fan is central, possibly to the left as when i push against the apple logo on the front of the imac it makes it louder.

Any ideas are great, thanks

09-18-2010, 02:26 PM

The machine is new. Let Apple sort it out for you under the warranty. Call and make an appointment with your local genius bar and take it on in. If one of the fans is defective they'll either repair it or just swap your iMac for another since it's new.

09-18-2010, 03:43 PM

Thats easier said than done. I don't drive and as you're aware the machine is a beast and getting it back from the store was a monstrous mission in the first place. To have to get it there and back again is a horrible thought so was thinking of a work around, but if nothing can be done - then i guess i'll have a mission on my hands!

Steve

09-18-2010, 04:15 PM

Sorry about the logistics... but you really don't have a choice since the Apple warranty does not cover "in home" or "at the office" repairs. Let us know how it goes. NOTE: Be sure to make an appointment first, otherwise you might lug your machine in only to wait around all day...

09-19-2010, 03:44 AM

I had a similar problem with a new i7 iMac although in my case the noise changed from quiet to the fan being on all the time.
Apple arranged a straight swap after the hard start ups etc failed to switch the fan off-it was under its 14 days warranty.

However what I did find awaiting the replacement completely unplugging the iMac and putting it elsewhere in the house saw it restart with the fan off and it stayed off.

Neither iMac ever gave the problem again. If you don't want to return it -it may be worthwhile switching it off for an hour or so and start it again or trying moving it. You may find as I did the fan didn't come back on again-that is of course if it is the same problem and I appreciate you may be describing something different.

09-19-2010, 02:58 PM

yea, thats definitely something catching on the fan.
Ive personally got 3 fans going on my computer, and 1 is at 2123 rpm, the other is at 765 rpm, and i can hardly hear them.

Is your computer in a hot area? When I moved into my dorm (no ac here) and started gaming, my cpu fan used to jump up to 3500 rpm (very nice jet engine imitation). Computers run on fans for cooling, and when your fans push in hot air, its not helping.
edit: the solution I found was to take one of the sides off my case and just put a box fan next to it, its louder but it works!
your under warranty though, so I would take it into apple and have them deal with it, not sure if its a good idea to open up your imac (if even can).

dust would be another issue, or cause, but since its new it wouldnt be it.

09-19-2010, 03:45 PM

I'm certainly not going to be opening a brand new imac to have a look at the fans. I left it unplugged for a while and turned it back on, still the same old noise.
The only thing i can describe it sounding like is when you go into a jungle/rain forest and theres loads of bugs making their noises. Cicadas etc.

Its kind of high pitched but not ear piercingly. Taking it back to the store is a mission but guess i have no alternative. I'll try and book an appointment now.

I'd also like to add, that i just now altered the minimum fan control speed with smc fan control and i heard each one of the three fans increase in speed, however the noise was not affected. Could it be the HDD?

09-19-2010, 05:22 PM

Regardless of what the noise is, your smartest option would be to take it to the Apple store.
Find some one who can take you, since you dont drive.

Good luck!

09-20-2010, 05:36 AM

I totally agree, i'll see what i can do about getting it back to the store. Just annoying as i need to use it but i don't want to install anything now as if its a faulty HDD then it'd prob just be replaced anyway....

Last night, i reset the PRAM again and after the restart the noise disappeared. When i turned it on this morning, it was back. So, the noise can go away, however it can also come back! Any ideas!?

09-20-2010, 07:22 AM

Box her up already....

09-20-2010, 10:39 AM

Originally Posted by stevolution

I totally agree, i'll see what i can do about getting it back to the store. Just annoying as i need to use it but i don't want to install anything now as if its a faulty HDD then it'd prob just be replaced anyway....

Last night, i reset the PRAM again and after the restart the noise disappeared. When i turned it on this morning, it was back. So, the noise can go away, however it can also come back! Any ideas!?

I might be wrong but I think you have a fan running when it shouldn't. Certainly if it was rubbing etc it wouldn't be affected by a restart.

Let us know the outcome, best of luck.

09-20-2010, 01:58 PM

Originally Posted by ZachUSAman

edit: the solution I found was to take one of the sides off my case and just put a box fan next to it, its louder but it works!

OMG!, that is so bad for your computer, doing that can cause so much damage!

Not to mention all the dust and other airborn particles you are blowing right into the electronics, that I'm suprised haven't shorted out the hardware already, and when you run the computer with that case off it removes the ESD protection for the system. The cases are designed to provide that protection.

09-30-2010, 01:31 PM

Any update on this?