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MarcoTogni

macrumors member
Original poster
Aug 12, 2017
38
19
Hi,
I bought an iMac 27" 5k (2017 model of course) and I received it 10 days ago.
Since 3-4 days ago I noticed after just some minutes it makes a kind of "electric noise" when the monitor is "used", I mean when I do something on the screen, even for simple tasks: scrolling, resize a folder, watching video etc. Especially when the brightness is at max level.
I am not talking about fan, I talk about the electric buzz you can hear in the video I made.
This noise is NOT loud, but it's possible to hear it, I can't work well with it and especially I think it may become a huge problem near the future.

My questions are:
- Is it normal? does your iMac do the same electric noise when you do something on the screen and the brightness is at max level?
- WHAT SHOULD I DO? I received it 10 days ago. Should I ask for a complete refund to Apple, and buy a new one?

Please check the video: of course I increased the audio so you can hear the buzz.



THANK YOU SO MUCH.
 
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Just some thoughts.

Plug headphones into the jack.
Does the buzz/hum go away?
Or is it still there?

If it goes away, could be in the audio signal (playing through the speakers).

If it's still there, could it be a "50/60 cycle hum"? Coming from (perhaps) the power supply?
Is the connection to the power outlet grounded?
 
All I hear in the video is I think a fan.


It might be the CPU.

Can't you hear the buzz???...
[doublepost=1502550516][/doublepost]
Just some thoughts.

Plug headphones into the jack.
Does the buzz/hum go away?
Or is it still there?

If it goes away, could be in the audio signal (playing through the speakers).

If it's still there, could it be a "50/60 cycle hum"? Coming from (perhaps) the power supply?
Is the connection to the power outlet grounded?

Thank you but it isn't from audio. I think it comes from the screen, I mean when the screen is used so it is "refreshed" it is possibile to hear this buzz..
 
Can't you hear the buzz???...
[doublepost=1502550516][/doublepost]

Thank you but it isn't from audio. I think it comes from the screen, I mean when the screen is used so it is "refreshed" it is possibile to hear this buzz..

I can hear something but I am not sure it's the sound I should hear.
It isn't easy to point out a problem over the internet, for instance, if someone has a problem with discolouring on a display and posts this on the internet but I have a bad monitor, I won't see it.
Now, it might be my speakers, or my hearing isn't what it used to be.;)

Edit:Just tried on my Yamaha, still can't hear it.
 
This might be coil whine, try different brightness levels to see if that changes the noise.
 
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I can hear something but I am not sure it's the sound I should hear.
It isn't easy to point out a problem over the internet, for instance, if someone has a problem with discolouring on a display and posts this on the internet but I have a bad monitor, I won't see it.
Now, it might be my speakers, or my hearing isn't what it used to be.;)

Edit:Just tried on my Yamaha, still can't hear it.

Yes of course is not easy to understand...
Should I ask for a complete refund to Apple, and buy a new one?
 
This might be coil whine, try different brightness levels to see if that changes the noise.

With less brightness the noise is less and disappears. But I can't always keep low brightness.. Any idea?
Thank you!
 
Just heard video, it definitely sounds like whine. Where from? Could be the video card or the monitor. Either way you need an exchange or refund.

Just to add, the buzz is hard to hear in the video but I’ve experienced this and it is not a minor thing, it’s very annoying. Usually happens on cheaper devices but some higher end graphics can also get it, doubt its normal for the iMac though.
 
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Just heard video, it definitely sounds like whine. Where from? Could be the video card or the monitor. Either way you need an exchange or refund.

I just searched on google, I think it's whine! I didn't know about it.
I would like to have an exhange but I am worried maybe Apple will say "we can't hear it" so they will not fix it...
That's why I am thinking to ask a refund and buy a new machine.
What do you think?
Thank you
 
In a busy apple shop they won’t hear it no, but iMac is a big device so not sure how they handle those, might come and pick it up if you have AppleCare+? Exchange or refund is your choice, to me the noise would seem quite obvious as you can even hear it in the video, in real life it should be clearer and will often match actions on the screen like moving a cursor or running intensive graphics. I have a video card with whine but all of them have it so put up with it, not that bad anyway but a monitor buzz that happens constantly is different.

Maybe call and see what support suggests.
 
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I'd recommend an exchange. Apple is excellent when it comes to these issues. A coworker went through 4 MacBook Pro exchanges in January before he got one where the keyboard wouldn't get stuck every time the machine got warm and Apple was helpful throughout.

Curious about the specs of your iMac though (cpu/ssd/ram). Some configurations (i.e. i7 cpu or 3rd party RAM or fusion drives/smaller SSDs) may be more prone to issues than others.
 
You might also try plugging your iMac into a power conditioner of some sort. You might have noisy power. Or take it to work and test it there.
 
have you tried changing the brightness level of the screen? Does the sound change or go away when yo do ?
 
I had this issue on an iMac before, I think the 2010.
Are you on a battery backup or UPS by chance?


On mine the sound would go away if the brightness was at it highest or near the lowest settings.
 
I had this issue on an iMac before, I think the 2010.
Are you on a battery backup or UPS by chance?


On mine the sound would go away if the brightness was at it highest or near the lowest settings.

Hi,
this noise appears when the noise is at max level. If I put the brightness lower, the noise is going away.
[doublepost=1502604726][/doublepost]
I'd recommend an exchange. Apple is excellent when it comes to these issues. A coworker went through 4 MacBook Pro exchanges in January before he got one where the keyboard wouldn't get stuck every time the machine got warm and Apple was helpful throughout.

Curious about the specs of your iMac though (cpu/ssd/ram). Some configurations (i.e. i7 cpu or 3rd party RAM or fusion drives/smaller SSDs) may be more prone to issues than others.

Thank you for your advice! I asked an exchange to Apple! I hope new iMac that will arrive will not have this problem.
It's an i7, with RAM installed by apple, 3TB Fusion Drive.
 
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The 2017 has some coil whine (I've had three and they've all exhibited it), it varies depending on the machine though, I could only ever hear it with my ear to the exhaust, on one it was quite loud (in that scenario) and the other two very quiet.
As someone who builds PC's I've found that it's extremely hard to find somewhat powerful GPU's that doesn't exhibit this in one way or another (I'm aware that the brightness affects it in this case, but just as an observation)
 
Hi,
this noise appears when the noise is at max level. If I put the brightness lower, the noise is going away.
[doublepost=1502604726][/doublepost]...

I cannot hear it on your recording but if it's high frequency, eg, 10-15 Khz your mic and the playback system might attenuate it.

In cases like this it is often useful to know the frequency or frequencies involved. A good way is using an audio frequency spectrum analyzer app like Spectrogram: https://itunes.apple.com/us/app/spectrogram-pro-with-super-smooth-60hz-update/id415301721?mt=8

Or SpectrumView: https://itunes.apple.com/us/app/spectrumview/id472662922?mt=8

With such apps you can turn up the brightness while observing the "waterfall" spectrum trace and see what frequency or frequencies manifest. If it's a single-frequency whine it would typically be a horizontal line in the higher-frequency region of the trace. If it has harmonics it would be multiple lines.
 
Hi,
this noise appears when the noise is at max level. If I put the brightness lower, the noise is going away.
[doublepost=1502604726][/doublepost]

Thank you for your advice! I asked an exchange to Apple! I hope new iMac that will arrive will not have this problem.
It's an i7, with RAM installed by apple, 3TB Fusion Drive.

BEST solution. It is not your job to diagnose a problem with a brand new computer. If it has an issue like this you made the right decision to return to Apple and get a new one.
 
Apple sent me a new iMac, but it has the same problem.
Do you think it's just my ear and I shouldn't care about this noise? But it's strange, even if I open just Safari on my iMac and I resize the window, I can hear it clearly!
It's a screen noise, I explain you why:
- if there is a background process and I don't do anything on the screen I can't hear it.
- if I do something on the screen, for example watching a video, resize a window, scrolling etc. I can hear it.

Don't you think it's strange the second iMac I received has the same problem?
thank you
 
Apple sent me a new iMac, but it has the same problem.
Do you think it's just my ear and I shouldn't care about this noise? But it's strange, even if I open just Safari on my iMac and I resize the window, I can hear it clearly!
It's a screen noise, I explain you why:
- if there is a background process and I don't do anything on the screen I can't hear it.
- if I do something on the screen, for example watching a video, resize a window, scrolling etc. I can hear it.

Don't you think it's strange the second iMac I received has the same problem?
thank you

It's probably coil whine, caused by resonant vibration of electronic components. Unfortunatley it tends to be installation dependent, which means it can be caused by your electrical setup, electrical supply and/or other devices on your electrical system. Generally speaking there's nothing you can really do about it if it's caused by your electrics rather than the susceptibility of the device, which is the other factor. Given that the second machine has the same behavior, it's probably your electrical system.

Probably the best thing you can do is try the device on another electrical socket or electrical loop, or try unplugging or moving other electrical devices you have nearby and see of the problem is reduced or goes away.
[doublepost=1503202328][/doublepost]
BEST solution. It is not your job to diagnose a problem with a brand new computer. If it has an issue like this you made the right decision to return to Apple and get a new one.
That assumes that Apple's machine is at fault.
 
Apple sent me a new iMac, but it has the same problem.
Do you think it's just my ear and I shouldn't care about this noise? But it's strange, even if I open just Safari on my iMac and I resize the window, I can hear it clearly!
It's a screen noise, I explain you why:
- if there is a background process and I don't do anything on the screen I can't hear it.
- if I do something on the screen, for example watching a video, resize a window, scrolling etc. I can hear it.

Don't you think it's strange the second iMac I received has the same problem?
thank you
Did you try the last iMac in a different environment or not? Did it have the same problem in a different location or source of power?
 
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