Vibrating case?

stijntje113 said:

When I hold my hand against the back of my new 27 inch Imac it feels like it vibrates a little bit. Is this normal for the computer?
If I put my hand on it you don't feel it. but only when I put my hand very lightly to the case or when i rub it very lightly.

Do other people have this? My brother and girlfriend did notice it immediately.. (without telling them)

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That's not vibrating, it feels like it but it is a tiny bit of electricity, many/most Apple Aluminium products have this, go and try to stand on a wooden chair, most likely the feeling is gone, or remove shoes on a tile floor, you feel it more.
With a laptop like a MBP you could easily test this by removing the mains, it is gone but the MBP will still work with internal battery, an iMac does not have this so the only way to test this out is to be isolated from the floor(grounding).

stijntje113 said:

When I hold my hand against the back of my new 27 inch Imac it feels like it vibrates a little bit. Is this normal for the computer?
If I put my hand on it you don't feel it. but only when I put my hand very lightly to the case or when i rub it very lightly.

Do other people have this? My brother and girlfriend did notice it immediately.. (without telling them)

Click to expand...

It's possible that one of the fans inside is off balance and creating the vibration. I once had a spider die inside the CPU fan and it threw off the balance so much that it sounded like a grinder was inside the iMac.

All apple devices has this feeling when they are in plug in
iphone ipad macbooks etc but when are charging or they are plug in, even if they are off.

Serban said:

All apple devices has this feeling when they are in plug in
iphone ipad macbooks etc but when are charging or they are plug in, even if they are off.

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Not ALL, most/all with METAL casings have, an iPhones 3GS does not have it, an Airport Express does not have it, a former (plastic) Macbook does not have it, and so on........

Metal= Most likely brushed Aluminium, you'll feel it more than on a smooth metal surface.

i refer almost all new devices with aluminium...this is the feeling of aluminium+charging

iMacs should not vibrate. This can't be normal.

Puevlo said:

iMacs should not vibrate. This can't be normal.

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It is completely normal for an Apple product to have this.

The problem is the power provider, in many western countries the common wire is grounded just before the meter in a house, but many do not or the grounding isn't as good anymore, this means the common wire is not 0 Volts anymore and if you touch the aluminium skin of an Apple product this tiny voltage/leakage will feel like vibration.

AC vibrates 50-60 Hz = 60 times a second.