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MacBook Pro at 220 volts, could feel current through aluminum case

It's leakage current from the mains power adaptor

The tingle you are feeling is leakage current from the power adaptor (ie the "brick").

My MPB power adaptor came with two country-specific mains plugs (Australia, 240v) - the first is a neat 2-pin plug which clips directly onto the power supply. The second is a standard (Australian) 3-pin plug with approx 1 meter of mains cord attached.

The third pin provides the earth connection.

When you use the 2-pin plug: tingles
When you use the 3-pin plug: no tingles.

Pity that Mac didn't include an earth pin on the plug adaptor which clips directly to the supply.
 
current

Hi guys,

I have used my MBP (US-bought) in Europe quite a bit and always had that grounding problem, presumably from using adapters without a real ground.

The last couple months I've spent in the Philippines and the electric system here is not really up to par. I'm getting shocks on most equipment in the house and the MBP of course showed the grounding problem again.

This really usually does not impact me (other than the tingling and random little shocks), but while here I started using a USB headset for Skype. With the case (and the the USB plugs) not properly grounded, the microphone is unusable because of static noise. I replaced the wall plug (two-hole outlet) with a grounding adapter and used the three-prong cable for the laptop and it got much better, but did not go away completely. The only thing solving the problem is to completely unplug the power supply from the laptop. It seems to me that I eliminated the grounding problem on the wire, but some current on the case is still there. How is that possible? I was going to ground that laptop case manually, but turns out the Philippines is a little short on radiators. ;-)


On a side-note: that laptop (and its power supply) is from early '06 and the MacBook Air I have with me as well does not show any problem like that, although I always plug it into the wall with a two-prong adapter on the power supply directly.
 
CaffeMacchiato said:
This is a common problem for macbook pro.

AC (alternate current) socket, be it 110 Volts or 240 Volts consist of two pins (life and neutral) and one ground (earth).

The cause:
By using just 2 pins (life and neutral) without using the ground pin, it is enough to transfer the energy to the adapter, which converts AC to DC (direct current) for the laptop. Thus, the body of the laptop chassis has a floating ground. Meaning, there is a difference between the ground potential of the laptop, and the ground potential of user (the real ground which the user is standing/sitting on).

The 'ground' potential of the laptop might be different from the 'ground' potential of the socket/real physical ground. When the user, with their feet connected to the ground, touches the laptop with their hand, it creates a current path for the current to flow from the laptop to the floor.

This problem could be resolved by,

(1) Using a real 3 pin plug. This will ensure that the ground potential of the laptop is the same as that of the physical ground. Therefore, there will be no current flowing from the user to the ground, even if there is a conducting path. No current flowing, no tickling sensation.

Note that some of their 3-pin plug provided has a fake ground pin (non-metallic). A real 3 pin plug would have a metal ground pin on both end of the cables.

(2) In some cases, those who sit on a plastic chair (non-conducting), could wear a rubber shoe, or lift up their legs to 'feel' the difference.
Click to expand...


Some countries don't necessarily have ground - my older apartment in Norway has no ground - and also has a floating neutral perhaps 100V above 'earth'. This has killed a number of PC TV cards (cable tv ground is earthed)
 
ndstrenge said:
you have no idea how absurd this sounds.

I'm well acquainted with non-grounded utilities. It's called- the third world. Take a shower in Peru and tell me how good it feels... or- ride an escalator in south east Asia... it's the same thing.
Click to expand...

how are showers in Peru?? - just curious :D
 
Does happen to me when i use the "NZ/AU DuckHead adaptor" (This does not have the grounding plug) How ever if i use the long lead works fine.
 
Tallest Skil said:
Ooh, ooh! I'm in Ireland right now, but I live and bought my MacBook Pro in the U.S.A. I get the same thing when it's plugged in! I think it's pretty cool, actually. A little tingly, vibratey sensation running over the bare case! Woot!

Wait, IS that normal? Probably not, but it doesn't break anything, so we should be cool...
Click to expand...

seems like you're one of those types that are into licking outlets for fun. mhm. of course it isn't normal! 220 can kill you, you dolt. have that thing checked out because you have a short somewhere waiting to zap you big time and it won't be pretty when you are sitting there wetting yourself because you're unable to control your bladder from the shock. dangerous, very dangerous.
 
I am thinking this is not supposed to happen...if it were me I would have it checked out.
 
HellDiverUK said:
1v can kill if the current is high enough. ;)
Click to expand...

No it can't - why don't people understand this?

Basic physics - human body has an average resistance - so you can have 5 TRILLION Amps at 3 volts - and NOTHING WILL HAPPEN. (unless you jammed a probe directly into your brain) Barring that, the amount of current that can flow through a resistive body at a fixed voltage is finite. If a human body was Zero ohms - then yes - you're boned. But up to 40 volts we're piss poor conductors, even with wet hands.

Higher voltages and frequencies changes the story - completely - but if the 1v could kill - I'd be dead already. I've bridged live sources @ 48V - in the thousands of amps, and I couldn't even feel it. My body, at most, was only conducting a few milliamps.
 
HellDiverUK said:
1v can kill if the current is high enough. ;)
Click to expand...

It is the other way around, 1A can kill if the voltage is high enough ;) Think it is around 60 milliamps to stop the heart, but that means the current gotta travel through your heart.
 
Anyone else get the feeling if Apple made cigarettes, people would start declaring cancer as "cool"? :confused:
 
XP Defector said:
Anyone else get the feeling if Apple made cigarettes, people would start declaring cancer as "cool"? :confused:
Click to expand...

It's not just Apple's machines that do it - they just happen to be made of metal.

I've been shocked plugging USB plugs into both 1Beyond and Dell systems while they've been connected to 220V.
 
XP Defector said:
Anyone else get the feeling if Apple made cigarettes, people would start declaring cancer as "cool"? :confused:
Click to expand...

You're blaming someone plugging a machine that was designed for 110 current into an ungrounded, unprotected outlet that puts out double the voltage on Apple?

How well do you think your toaster would function if you plugged it in where your washing machine goes?

(Don't try this.)
 
I am having the same problem with the two pong wallplug. I have just talked to Apple and they will send me the three plug AC cord. Hopefully this will fiz the issue.
I am right now running my MBP with out the Magsafe plugged in and it seems to have gotten much better but I can't tell if it is still there or not, it kinda feels like it is but my mind could be playing tricks on me since im getting a little paranoid over this issue.
 
Rampant.A.I. said:
You're blaming someone plugging a machine that was designed for 110 current into an ungrounded, unprotected outlet that puts out double the voltage on Apple?

How well do you think your toaster would function if you plugged it in where your washing machine goes?

(Don't try this.)
Click to expand...

You are misinformed. Usually when I make a mistake like that...especially if I said something rude like you did I would apologize. You going to?
 
Lucbert said:
I am having the same problem with the two pong wallplug. I have just talked to Apple and they will send me the three plug AC cord. Hopefully this will fiz the issue.
I am right now running my MBP with out the Magsafe plugged in and it seems to have gotten much better but I can't tell if it is still there or not, it kinda feels like it is but my mind could be playing tricks on me since im getting a little paranoid over this issue.
Click to expand...

If you can't feel it without mains power I wouldn't try to hard to do so ;) But seriously I feel it on battery only but much less...the palm rest and touchpad protectors stopped me from noticing it. It is obviously connected to the metal body conducting current somehow. It has happened with other metal laptops in fact Dell had a press release in the past how it was "perfectly normal" when people started complaining about one of their models. Whether it is harmful or not it is irritating...and something Apple would never address publicly because of the sheer amount of money it would cost them. Especially since people would come out of the woodwork suing them for various maladies. If they ever do address it then it will be quietly in engineering revisions but not out loud.
 
This horse has been throughly flogged, but here is my experience...I've been using Macs bought in the States for years in Europe (France, Spain, Italy) and I've never gotten a tingle. But then again I never use the little adapter to plug the brick into the wall, I've always used an extension cord with the correct ground (only because I like the extra mobility provided by a longer cable).

The power supply and the computer power circuit is the same if you bought it in Japan, Australia, Norway, or America. All the brick adapters take from 100 - 240 VAC. Its clearly printed on the adapter.

Anyway, enjoy the tingle!:)
 
Ok I got my new European Union extension cord today. Ill see if the tingle/shock happens when using it or no... I hope NOT!
 
Has anyone with a "tingling" Mac laptop thought to try testing with a voltmeter between the surface of the laptop and a known ground, to see if there is any voltage present?

I don't have one to test, or I'd try myself.

- John
 
Kilamite said:
You can get the same effect from most external hard drives that have a power supply. Run your MacBook Pro on battery, and plug in your external hard drive. You'll get the same effect.

It is just because of the aluminium case.
Click to expand...

I am having exactly the same problem. The only difference is:
- Plugged in (3Pin): No problem
- Plugged in (2Pin): Feels weird
- Battery, external HDD connected: feels weird
- battery nothing connected: No problem
- Plugged in (3 Pin) with HDD connected: first there is nothing but if I keep the hdd plugged in the issue will eventuall show up which is weird as the computer is grounded with a 3 pin. Maybe the external HDD is defective?
 
Fishrrman said:
Has anyone with a "tingling" Mac laptop thought to try testing with a voltmeter between the surface of the laptop and a known ground, to see if there is any voltage present?

I don't have one to test, or I'd try myself.

- John
Click to expand...

As far as I know there is, I mean thats what is causing the problem.
 
maybe taking your mbp to another country just makes it do this? cuz like everybody either lives in us and goes to europe or lives in europe and goes to us.
 
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