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casjohnr

macrumors 6502
Original poster
Aug 31, 2007
288
276
When I first powered up my new 20" Alu iMac it was dead silent.

Suddenly the fans came on and now it remains at a continual 'hum' sound - 998RPM optical drive and 1199RPM CPU Fan / Hard Drive. 40oC.

Is the hum normal or do I need to get it checked out?
 
The fans won't go slower than the values you posted so that's normal. It could possibly be the HDD you are hearing, or perhaps the screen (there was a humming issue with the previous 24" model iirc), it could also be that one of the fans are unbalanced.
 
It wasn't dead silent when you first powered up, you were either just soo excited or had significant background noise you didnt notice the hum until when things were quieter.

The fans stay around 1200rpm so fan speeds are normal and the hum isn't all that bad is it. It seems to be barely more audible than a laptop....maybe thats just me
 
The fans stay around 1200rpm so fan speeds are normal and the hum isn't all that bad is it. It seems to be barely more audible than a laptop....maybe thats just me

Except that it doesn't get louder when you do CPU intensive tasks. Which is one of the reasons I got the iMac to complement my MacBook.
 
I switched to my 20" iMac from a five-year-old Compaq PC, and compared to the Compaq, my iMac just seems absolutely silent. Yes, when there's zero background noise, I can hear a faint hum from the iMac, but for my purposes, the 20" iMac is as quiet as I could ever hope for.

What I don't get is how Apple can create a 20" all-in-one computer with such low noise, yet Microsoft's Xbox 360 sounds louder than the oldest, loudest PC I've ever had. Is Apple doing something right, or is the Xbox doing something so incredibly wrong? Hmmm.
 
The key is that the iMac uses laptop parts which are much cooler but a bit more expensive than desktop parts.

No, it doesn't incorporate ALL laptop parts. The noisiest part of any computer tends to be either the fans or the hard drive and the iMac uses desktop class hard disks. When's the last time you've seen a 1TB 7200 rpm hard disc in a laptop.
 
I had the same issue with my 24"

My new 24" did the same thing...then the hum was constant.

I called apple and they replaced my machine. My new one is on the way. I am anxious to see if it is as quiet as everyone else has described their new machines.

I checked all of my fan and drive speeds, as you mentioned, with apple tech guys and they said they were all normal, but the hum still was present.

For what it is worth...
 
Yep I'm gonna go try getting it replaced, especially since I need to also get them to look at why their official cleaning cloth has streaked the glass display to hell!

But hopefully they will pick it up from my house and ship a replacement out as if I took it into Apple Store they would not be able to hear the noise! I heard they stopped offering the whole mail in service for the UK but since it is a replacement I am after it should be OK (I hope?!)
 
My new 24" did the same thing...then the hum was constant.

I called apple and they replaced my machine. My new one is on the way. I am anxious to see if it is as quiet as everyone else has described their new machines.

I checked all of my fan and drive speeds, as you mentioned, with apple tech guys and they said they were all normal, but the hum still was present.

For what it is worth...

Yep I'm gonna go try getting it replaced, especially since I need to also get them to look at why their official cleaning cloth has streaked the glass display to hell!

But hopefully they will pick it up from my house and ship a replacement out as if I took it into Apple Store they would not be able to hear the noise! I heard they stopped offering the whole mail in service for the UK but since it is a replacement I am after it should be OK (I hope?!)

Not to be a downer but there's a high chance you'd both be wasting your time, the new machines will still have the same hum.....just part of the cooling process. Hopefully am wrong though
 
My new 20" Imac is noisy too!

Hi friends,

This is my first post and my first mac. I love the computer, but the constant humming noise is really driving me crazy.

I notice if I tilt the screen forward it's not as bad, but I shouldn't have to do that. It's even louder than the music I'm playing. It's sounds like a small refrigerator.

It's almost constant, the first minute or two are quiet though, but once it warms up, the humming begins.

I called support and they suggested I take it to the Apple Store. I did, but it was so noisy and crowded they couldn't hear anything. Also, the guy helping me had never worked on the new Imac 20" so he didn't know much about how it should sound. He said after time, maybe the humming sound would go away, or just the drive in the car with a couple little "bounces" would settle it down. Basically, he just wanted to move on to the next customer.

Anyway, what do you guys think I should do? Should I push for an exchange?

Here are the details of my machine.
Processor 065-6838 2.4GHz Intel Core 2 Duo
Memory 065-6828 2GB 667 DDR2 SDRAM - 2x1GB
Hard Drive 065-6842 750GB Serial ATA Drive

I do like my Imac, but I don't want to live with this noise for the next several years.

Thanks for your help!
 
Hi friends,


I called support and they suggested I take it to the Apple Store. I did, but it was so noisy and crowded they couldn't hear anything. Also, the guy helping me had never worked on the new Imac 20" so he didn't know much about how it should sound. He said after time, maybe the humming sound would go away, or just the drive in the car with a couple little "bounces" would settle it down. Basically, he just wanted to move on to the next customer.

Did you set up an appointment at the Genius Bar? You should get much better service there. I had a fan which made a slight ticking sound. They took it into the back where it was quiet and I was out of the store with a new machine in under 15 minutes.
 
Did you set up an appointment at the Genius Bar? You should get much better service there. I had a fan which made a slight ticking sound. They took it into the back where it was quiet and I was out of the store with a new machine in under 15 minutes.

Yes, I did take it to the genius bar and I had an appointment. I guess I'll try again, maybe at another apple store.

I'm glad your problem was quickly resolved though. Hopefully, I'll get better service next time.

Thanks for the reply.
 
i've had my imac for a few weeks now and i can tell you that it is completely silent... i hope you get things worked out!!
 
still noisy, but possible diagnosis

i've had my imac for a few weeks now and i can tell you that it is completely silent... i hope you get things worked out!!

I made my second trip back the genius bar. They kept it for a couple days. They said it checked out fine, although I compared to the other Imacs on display, mine was much noisier and hotter. Again, they said it checked out fine and to run the update.

The tech said a new update was available from mac. They didn't have time to download it but said I could download it using the update feature.

I wasn't able to find the update so I called tech support. They could find no evidence of an update for fan noise.

The tech on the phone had me do some diagnostic tests and actually reinstall Os x. He thought that might resolve some of the fan noise, because we concluded all the fans are on all the time, and that's a big part of the problem.

After reinstalling OS x, there was still noise. The tech said to take it in for repairs. This time I took it to an authorized service facility. The tech said that I have a problem with the logic board. It's a huge job to fix it and they'll have it for at least a week.

I'm glad the problem may possibly be resolved, but I'm very disappointed with the Apple Store for the poor service they've provided. They didn't even call me when my computer was ready to pick up.

I'll keep you all "posted" as to how this works out, just in case you're having the same problem.
 
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