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northy014

macrumors regular
Original poster
Aug 26, 2008
157
0
When I run a finger down the case of my Alu MacBook, sometimes it almost feels as though there is electricity running through the case, and I get a very (very) mild electric shock, it almost feels like a vibration. Anyone else getting this?
 
No shock here, but that vibration you're talking about yes. But only when I'm charging the MacBook. Not otherwise. And thats because it's incoming electricity into the battery, which is located right underneath the keyboard - which is where you feel the vibration right?
 
I get that when I rub the macbook. But it happens anywhere around the keyboard, not just by the magsafe. I think it is just the material and tecture rather than a current, but I can see why it may feel like a current.
 
It's normal behaviour. In fact it's designed to do that. I got this information with all the details (which I can't remember now) from someone at Apple but rather than shocks I think you are referring to a tingling sensation. If it is a shock I'd take it in for repair.

I imagine you are using an electrical installation without ground wires or are not using the power cord with the ground pin.
 
Yeah, it is by no means a vibration. If it was a vibration, why only when it is plugged in?

It's normal behaviour. In fact it's designed to do that.

I doubt very much that electric current is supposed to run over the case and through me to ground. If it's "designed," what is it designed to do?

It seems to me that the plastic where the magsafe plugs in is not thick enough to act as a complete insulator and that some charge is jumping through the dielectric into the aluminium, and then through peoples' touch to ground.

I imagine you are using an electrical installation without ground wires or are not using the power cord with the ground pin.

I know for a fact that this houses' electrical wiring is properly grounded and that I'm using a cord with a ground pin.
 
I doubt very much that electric current is supposed to run over the case and through me to ground. If it's "designed," what is it designed to do?


I know for a fact that this houses' electrical wiring is properly grounded and that I'm using a cord with a ground pin.

I can't remember all the exact details but I seem to remember the one situation it shouldn't happen in is the one you've just described.

I do remember that I also found a complete description online of why this was designed that way but I can't find it at the moment. If I locate it I'll post a link
 
i have the same sensation.
when i run my hand on the aluminium part when plugged in, sometimes i felt like a high frequency vibration as if it allows the fingers to slightly float along the aluminium. i wonder what if not some grounding problems from the electricity. it is definately not current, coz that will kills.
 
It won't kill you... This has been discussed many times in the MBP/MBA forums. I have it on multiple machines when plugged into certain plugs but not others. New AlumiBook owners, welcome to the world of Apple metal laptops!

I kind of like the way it feels.:D
 
It's actually secret technology Apple is working on in an attempt to brainwash people into buying more Apple products...
 
It's the nature of a switching power supply. (the kind that apple uses in their power supplies) You're not truly isolated from main power like you would be with something with a transformer in it.

To reiterate - yes this has been discussed many times before - and it has been explained, too. Searchy.

In short - if you are truly bothered by it - acquire a 1:1 / isolation transformer. (something like this http://www.amazon.com/Tripp-Lite-IS...2?ie=UTF8&s=electronics&qid=1226212204&sr=8-2) Isolation transformers physically isolate you from the mains - so that sensation will go away with it.

As for the sensation, it's not dangerous, more things do this than you're aware. Just most things don't have metal cases tied into them. I'm sure MANY other laptops would do it if they too, had metallic cases.

My old dell mp3 player did it when it was charging.
 
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It happens to me as well, it's not the only thing that did it either. An old Sony MiniDisc deck did the same as well.

It's weird cos some MB, MBA and MBP do it whilst others don't, my Mac keyboard (Alu) is fine :)
 
It happened to me to. Went to the apple store and they said it's perfectly normal. The models in the stores have it as well.
 
Does this cause damage to components?

Ok, I've got this new found problem with my unibody macbook (2.4Ghz). I'm just visiting some family at the moment living in their house, and have noticed that this problem only exists here. A house problem?

Well, I want to know if anyone has knowledge or experience on whether this causes component damage to the MB or MBP?

No one in the previous posts have mentioned this. I did post this on the MBP forum as I didn't find this forum until after my post. Apologize for double post.

Thanks.
 
I've noticed this with my MB over the last few weeks. I'm in the UK though and all our plugs are earthed. It's worrying me!
 
use the long cable given in the box. The short plug has problems with earthing.
 
I've experienced something similar, but it was caused by the rapid temperature differences over a short area. Namely the bottom of the machine and the screen, both of which were touching my lap (the screen being cool).
 
I have the exact problem. When it is 'charging'. BTW, I mostly have my MacBook connected.

But I'm sort of living with it as its very mild, and is a bit more pronounced when you move your had over the metal.

Earthing problem is it?

EDIT: Oh I get it. But isnt current leak dangerous for the device.
Also, the back of my iPod Touch gives a similar sensation, at least at times I have noticed.

bjfong said:
use the long cable given in the box. The short plug has problems with earthing.
That does not help.
Though yeah, if one is having problems with earthing, using a 3-pin is highly recommended. Not using that could be dangerous.
 
tingling sensation

I get this tingling sensation even when it runs on battery power. The strongest sensation appears to come from the area near the sleep indicator light on my Unibody Macbook. I believe the other opening is for the airport antenna? I put on a grounding strap, shut everything down, and took the battery out. A screw that fastens the antenna (what I think is the antenna) was a little bit loose. I tightened it. The sensation remains.

When plugged in, I have this plugged into an APC UPS device with the 3 prong cord, and all indicators on the unit suggests that the outlet is properly grounded.

I'm reading from earlier posts that this is "normal." At what point should I be concerned? Are there indicators that would suggest that I have a problem beyond what is considered normal? I'm not an electrical engineer, and always appreciate the knowledgeable feedback I get here. I will keep Googling this as well.

EDIT: I have not noted these sensations on my titanium powerbook G4 plugged into the same spot as this MacBook.
 
I've just started having the 'vibrating' feeling on my late 2008 aluminum MacBook, too. It concerns me more than a little. I know the outlet I'm using it in is not grounded, but I've been using it there for a while with no issues and no vibrating. The previous address I lived at also had no grounded outlets and I never had any trouble. Should I be worried?
 
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