Electric shock from MacBook Pro while charging only.

Anyway, I'm very skeptical that people are experiencing electrical shocks from their MacBooks.

Yeah, well, I think you should give people more credit for knowing what an electrical shock feels like. I bought mine at the beginning of April and every once in a while I would feel something like a sharp needle under my wrists. I've been wondering if it was hairs on my arms getting pinched in between the metal frame and the plastic grey band that surrounds it. Until today. It was so sharp I had to my arm back immediately. I tested it in different places and it was clearly an electrical shock.

Hadn't heard or read about the issue before. I googled "MacBook Pro" electric shock and what do you know.....other people have experienced it, too.

I plan on buying a MacBook Pro in the next six months and will conduct the touch current tests described in UL 60950-1 in my lab after I receive one. I also contacted the agency who certified the MacBook Pro to UL 60950-1 and made them aware of the complaints about electric shock, but I suspect the MacBook Pro does not exceed the maximum touch current permitted by the standard.

I think your problem could be static, I get the same with my Dell PC and MacBook Pro.

Walk across the carpet, get static charge, touch laptop casing and shock.

I don't think you have anything to worry about but I suggest you get it
checked out.

Suffy........ 🙂



MacBook Pro Mac OS X (10.4.6)

I think your problem could be static, I get the same
with my Dell PC and MacBook Pro.

Walk across the carpet, get static charge, touch
laptop casing and shock.

If I were doing that. But sitting at a desk without moving and touching the pad with my wrists and receiveing shocks every time I make contact, then (without moving my body except for my left arm) unplugging the power chord and not receiving shocks would seem to indicate otherwise.

But yeah, I'll definitely have it checked out. Writing term papers is torture enough as it is without having to endure electric shock...

Am I the only one who finds this electrically impossible? The voltage coming out of the adapter is DC low voltage. To feel this on the skin would require very sensitive fingers that are wet and even then, near impossible to feel. If the lack of ground from using just the 2 prong causes this, it would indicate there is AC current coming down the wire. If this were the case, the laptop would instantly have severe issues if run at all.

The failure of the conversion from AC to DC would be immediately noticeable. The only thing needed to convert is 2 diodes. If either fail, DC is not created.

Next comes voltage, it is created to a specified range. Usually a very small range. If the output voltage is 18 volts but it is putting out 20 volts, you get extreme heat issues and random lockups. If it puts out 16 volts, you'll get logic problems within the system.

My guess, look at something else. Put the laptop on a piece of glass and see if it happens.

Or, I could be completely wrong.

You can come over and feel my MBP buzz if you want. It hasn't shcoked me, but at times there's some electical potential and you can feel it if you put your fingers lightly on the laptop palmrest (and no, it's not the hard drive).

For what it's worth, I only feel it on the (sensitive) underside of my wrists/arms that are in contact with the outer edge of the computer when I type. When I touch it with the pads of my (calloused, but dry) fingers I don't feel it.

But the area is definitely right where the aluminum case meets the grey plastic border.

And I've just tested again this morning. I unplugged the 3-prong, plugged the two prong in and presto, electric shock. The weird thing is, it isn't always constant. It's intermittant, which is probably why I've gone so long thinking it was something else. Very weird.

It's sitting on a laminated fibreboard desktop. Would that make any difference?

Actually it is not electrically impossible. The backlight inverter within the MacBook Pro outputs high voltage. If there was a fault between the backlight inverter and the aluminum case the user could experience a high voltage electrical current, but it most likely would not be at a hazardous level.

How would that circuit produce a potential between the case and ground when the case is itself at griound potential? Or between any two points on a case that is conductive?

Right. It cannot.


RRS

From the posts I have read the user only gets shocked when using the unearthed mains connection which allows the MacBook Pro case to float. I suspect some users are actually experiencing high voltage current, but it is at a safe level.

Current must be drive through a circuit. If the illumination inverter’s high-voltage output is causing a current through the user touching the case of the MacBook Pro, then it must connect, however indirectly, with both the case and some other part of the person’s body. I don’t see how something internal to the device could do that.


RRS

Look, I don't understand very much about electrical currents and their conductivity, so I have no idea why this occurs. But the fact is, it's happening.

Sometimes, it's the "tingly" sensation described previously, also felt through my fingertips I've now noticed if I put them on the edge where aluminum meets band. At the time of my first post, it was a significant jolt. At least enough for me to take my arms away immediately and wonder what in the world was going on. That hasn't happened again.

It seems to be particulary noticeable/strong during recharging of the battery. I let it run until sleep and then as soon as I plug it in (the two prong) I can feel the buzz. I think when it's fully charged though, it's practically non-existant. Right now, though, I can feel it in my wrists. It's fairly regular and at some point I have to lift my wrists from the edge because they start to throb uncomfortably from it. Other times it's the tiniest of jolts.

To anyone who thinks it's relevant I'm using an american plug through a British adapter. But it shouldn't make any difference. And indeed when I plug in the 3 prong into the adapter the problem essentially disappears....

Anyway, I hope to have it checked out sometime next week at an Apple Store.

Did you read the comments by Peter Arnold1 that I quoted above?

Just because you have a sensation that seems like electricity does not mean that you're being subjected to an electrical current.


RRS

But if the sensation is present when plugged into AC and absent when running on battery, and then present again immediately upon plugging in the AC, I think that discounts the psychological affect described and does have something to do with electricity. I don't have to move my fingers around to feel the effect though, as stated in that post.

Yes I did. He talks about movement:

"the feeling as you rub your fingers across brushed aluminum", "signals of a certain frequency generated by moving the finger across the ridges of the aluminum surface", etc.

And yes, when I follow his instructions, I do feel the lightest of tingling sensations in my fingertips as I brush them back and forth across the aluminium.

What I've been experiencing is a different sensation and occurs with no movement. I can simply place my wrists on the specified area and feel whatever it is you want to call it. And it can be sharp and sudden on occasions.

Furthmore, Arnold's comments do not account for the two prong vs. battery/three prong discrepancy in the occurrence of this particular phenomenon.