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Level 1

11 points

Strange vibration felt through fingertips when plugged in

In all my years of working in IT, I've never encountered this.

It seems when I rub my fingertips on the lid of the MacBook Pro (only two months old) when the power adapter is plugged in, my fingers feel this weird sensation of vibration -- as though they were brushing against rubber.

But when the laptop is running on battery power alone, the sensation does not occur.

My wife confirmed this so I'm not totally nuts here. I also tried to see what would happen with the battery out but plugged in -- the "problem" persists.

This is clearly some weird electrical problem. Should I be concerned?

Macbook Pro, Mac OS X (10.4.10)

Posted on Aug 6, 2007 11:20 PM

Best reply

dvbfilth

Level 1

5 points

Posted on Aug 7, 2007 1:23 AM

Its a grounding issue. If you're using it on battery power or with the three pronged (US) plug that comes with it, it doesnt happen.

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18 replies

dvbfilth

Level 1

5 points

Sep 20, 2007 6:54 AM in response to prasadvenkat

It definitely is an earthing problem. I got the UK travel kit thinking that it would go away if I used their 3 prong plug in that. However if you look closely to the contacts you'll notice that the one for the 3rd (top) pin doesnt actually go anywhere, which is why some with the 3 pronged plug are still getting the buzzing sensation.

solucien

Level 1

0 points

Sep 24, 2007 7:53 PM in response to eriksr

yes same problem here.
looks like its worse on my visits to china, they might run a more unstable and higher currence.
but i feel it very often. small shocks on your bare arms/wrists. first I tought small hairs got caught between the alu casing and the plastic edge, and were pulled out. but then i noticed the static vibration when running my fingertips on the casing. and its everywhere, on the lid, on the surface around the trackpad.
surely hope this doesn't affect the lifetime of my laptiz...

Message was edited by: solucien

Sep 26, 2007 3:28 AM in response to solucien

I encountered this "electrical" vibration with the aluminium case of the MBP at 2 different stores that have MacBooks displayed for sale, in France and Germany. I am quite close to buying one, but this has me a little worried. So I am trying to check out what this is about, since it does seem to involve electricity.

I found something about electrical fields causing "buzzing" in electrical appliance cases where there is a hot wire, a bad thing. But they only refer to AC. And I thought (assumed ?) the power adapters supply only DC current to the Mac.

Strange! Any answers from Apple ?

Strange vibration felt through fingertips when plugged in