Become a MacRumors Supporter for $25/year with no ads, private forums, and more!

How to resolve vibrating/'electric shock' sensation from MBA?

NewBench

macrumors regular
Original poster
Jun 24, 2010
231
172
I've googled this and couldn't find any clear answers. A relative's 2020 base model (i3) MBA gives a vibrating sensation which is apparently a very minor electric shock when anywhere but the trackpad or keyboard keys are touched. Anywhere metal (obviously). I tried it myself today and also experienced it. It's not painful or uncomfortable, but it's 'there' and persistent.

I have a 16" MBP and have had a couple of recent 13" 2020 MBPs and none of them have this issue despite being made of the same materials.

We're in the UK, and some of the results on Google seemed to suggest this might be something to do with poor grounding of our 3-prong wall sockets?

- Is this a fault with the MBA or a house wiring problem?
- Is this issue exclusive to the MBA (as I didn't experience this with 3 different MBPs)?
- How can it be resolved?

Thanks
 

IngerMan

macrumors 68000
Feb 21, 2011
1,828
716
Michigan
In the USA this solves the problem, maybe they sell the same thing for a UK plug?

D3801051-65B2-4A91-845A-8946B9EF6969.jpeg
 
Comment

NewBench

macrumors regular
Original poster
Jun 24, 2010
231
172
In the USA this solves the problem, maybe they sell the same thing for a UK plug?

View attachment 930770

Thanks. I'm sure I've seen something similar. Still wondering why this is only happening with an MBA and not the MBP. You would think Apple would have come up with a solution for this (that doesn't involve buying a $19 cable).
 
Comment

Erehy Dobon

macrumors 68000
Feb 16, 2018
1,614
1,452
No service
This sounds more like a house wiring problem than a design issue with the MacBook Air (of which millions have been sold).

This leads to more questions.

Does this relative experience the same problem in other locations outside his/her residence?

Do you experience the same issue with your Apple hardware in your relative's domicile?

One thing to try would be to use a GCFI tester in the relative's house to check if the wiring is faulty. If it is it should be properly remedied by a licensed electrician. We periodically see MR commenters bring up their issue, it is almost always something specific to their location.

If the electrical outlet is properly wired, it really shouldn't matter whether or not the cable is grounded (3 pins) or not (2 pins). Sure, the grounded outlet is a bit safer but you shouldn't be receiving a jolt on an ungrounded outlet.

It's notable that some countries don't even have grounded household outlets. I know Japan is one of these.
 
Comment

NewBench

macrumors regular
Original poster
Jun 24, 2010
231
172
This sounds more like a house wiring problem than a design issue with the MacBook Air (of which millions have been sold).

This leads to more questions.

Does this relative experience the same problem in other locations outside his/her residence?

Do you experience the same issue with your Apple hardware in your relative's domicile?

One thing to try would be to use a GCFI tester in the relative's house to check if the wiring is faulty. If it is it should be properly remedied by a licensed electrician. We periodically see MR commenters bring up their issue, it is almost always something specific to their location.

If the electrical outlet is properly wired, it really shouldn't matter whether or not the cable is grounded (3 pins) or not (2 pins). Sure, the grounded outlet is a bit safer but you shouldn't be receiving a jolt on an ungrounded outlet.

It's notable that some countries don't even have grounded household outlets. I know Japan is one of these.

I'm not too technically minded when it comes to wiring, but can get someone to check to see if its faulty - I'll mention what you have suggested.

What I don't understand is why it only seems to be an issue with the MBA. I took my 16" MBP over there tonight and plugged into the same socket and didn't experience any shock, but when she plugged her MBA back in, I could feel a small electric shock from the metal areas of the case.

Both obviously use a USB-C cable connected to the Apple brick with a 3-pin plug slotted into it - all are genuine new Apple items from the box the MacBooks came in. The only difference is the 16" MBP has a larger 96W adapter, and the base MBA uses a 30W.
 
Comment

Erehy Dobon

macrumors 68000
Feb 16, 2018
1,614
1,452
No service
Try using your relative's MBA 2020 with your 16" MBP's charger. There's no problem using the 96W charger with the MBA, the charging device tells the AC charger how much current to send.

If there's no electrical shock, then there's a problem with her MBA's charger and/or the cord. You can try switching the 3-prong extension cords to narrow it down.

In fact, you can plug your 16" MBP into her MBA's charger. It is not powerful enough for your system to maintain a full charge if you are actively using it, but again if you feel a shock, that would likely confirm that there's a fault with her charger.

If there is a shock using your MacBook's charger, that would indicate some sort of internal defect with her MacBook's power circuitry.

The extra information that you are able to use your 16" MacBook Pro at her place and the same outlet with no problem does not point to a house wiring problem.

You did not answer my question whether or not your relative experienced the same shock if she plugs her MBA into an outlet away from her house.

For sure, she could bring her MBA into an Apple Store. They will definitely have power outlets that are correctly wired. It's not in Apple's interest to have customers shocked in the store when they plug in their computers.

Also, you did not report whether or not your relative tried any other outlets in her house.

You need to provide many more answers to narrow this down.
 
Last edited:
Comment

Secubia

macrumors member
May 4, 2019
43
19
Stockholm, Sweden
I think this happens when using an ungrounded charger, extension cord or electrical outlet. This happens with any devices that have metal surfaces. If the entire "chain" is grounded you won't feel that vibrating when touching the surface of the device.
 
Comment

NewBench

macrumors regular
Original poster
Jun 24, 2010
231
172
Try using your relative's MBA 2020 with your 16" MBP's charger. There's no problem using the 96W charger with the MBA, the charging device tells the AC charger how much current to send.

If there's no electrical shock, then there's a problem with her MBA's charger and/or the cord. You can try switching the 3-prong extension cords to narrow it down.

In fact, you can plug your 16" MBP into her MBA's charger. It is not powerful enough for your system to maintain a full charge if you are actively using it, but again if you feel a shock, that would likely confirm that there's a fault with her charger.

If there is a shock using your MacBook's charger, that would indicate some sort of internal defect with her MacBook's power circuitry.

The extra information that you are able to use your 16" MacBook Pro at her place and the same outlet with no problem does not point to a house wiring problem.

You did not answer my question whether or not your relative experienced the same shock if she plugs her MBA into an outlet away from her house.

For sure, she could bring her MBA into an Apple Store. They will definitely have power outlets that are correctly wired. It's not in Apple's interest to have customers shocked in the store when they plug in their computers.

Also, you did not report whether or not your relative tried any other outlets in her house.

You need to provide many more answers to narrow this down.


Went over there today. We tried two ground floor outlets and a first floor outlet. When plugged in, we still felt the same sensation. We also had the earth/ground connection tested at the main fuse box and that came back as working as it should be.

I tried my MBP with her charger and didn't feel anything unusual. To me this suggests its the MBA itself.
 
Comment

dave255

macrumors newbie
Oct 29, 2019
8
7
Hi I had the exact same thing! with my MPB 2017 this weird tingling when touching it. I remeber googling at the time and some people are more sensitive to it than others. I swapped the cable (between the uk plug and the duck head) for my old mac book air one and the issue went away. Also using the MBP cable on the air the I could feel the same thing on the air. Anyway get an extension cable they have the ground wired in correctly (https://www.apple.com/uk/shop/product/MK122B/A/power-adapter-extension-cable) and you should be ok.

Some more info here https://apple.stackexchange.com/questions/17575/how-to-properly-ground-a-macbook-pro
 
  • Like
Reactions: IngerMan
Comment

Ruggy

macrumors 6502a
Jan 11, 2017
505
286
Do any Mac chargers have an earth? Yes, in the UK you will have a 3 pin plug of course, but are there three wires in it or just two? In Europe, all the chargers only have 2 pins/wires and on the iphone charger with interchangeable socket adapters, they only have two wires. I doubt very much it'll have an earth
in the pic someone posted above the wall end has three pins but the other end only has two wires.
Very few pieces of electrical equipment outside the kitchen will actually have an earth wire on them these days. Occasionally an electric fan or air conditioner unit and some PCs but not much else.
I have felt this myself but I don't see how it can be an earthing problem if there's no earth.
[automerge]1593981666[/automerge]
Do any Mac chargers have an earth? Yes, in the UK you will have a 3 pin plug of course, but are there three wires in it or just two? In Europe, all the chargers only have 2 pins/wires and on the iphone charger with interchangeable socket adapters, they only have two wires. I doubt very much it'll have an earth
in the pic someone posted above the wall end has three pins but the other end only has two wires.
Very few pieces of electrical equipment outside the kitchen will actually have an earth wire on them these days. Occasionally an electric fan or air conditioner unit and some PCs but not much else.
I have felt this myself but I don't see how it can be an earthing problem if there's no earth.
Anyway, it's not working on mains voltage is it? The mains side goes into the transformer doesn't it (or is the air different I don't have one? ) Surely what gets to the Air is 12V or 24v or something like that.
Just checked: output 5v 3 amps. and it's the same charger with the interchangeable socket at the plug end so definitely no earth.
 
Last edited:
Comment

georgB

macrumors member
Jan 7, 2004
77
73
Europe
While faulty grounding in the house's sockets may be at fault, the main (and perhaps more usual) problem is with Apple's faulty power adapter plug. I just got a 2020 MacBook Air, and noticed current leakage (a tingling feeling when touching the metal) which I never had with any MacBook before. It's only mildly disturbing, but I suspect it's probably not healthy for the computer, either. Searching the internet, I found a number of suggestions pointing to faulty grounding of the household wiring. That may be true for some, but the sockets (in our house in Austria) are all fine - properly grounded.

The problem is Apple's power adapter cord. The one that came with my new MB Air was 2-pronged - no ground connection. The MB power adapters up to now have always had a ground connection. The solution was simple: I replaced the plug on the new adapter (easily slides off) with one from an older adapter, and now there's no more current leakage. I can't understand why Apple ships a problematic plug with the new power adapters when they used to ship a better - grounded - cord, which is probably healthier for the Mac.
 
Last edited:
Comment

deeddawg

macrumors G4
Jun 14, 2010
10,284
4,023
US
The problem is Apple's power adapter cord. The one that came with my new MB Air was 2-pronged - no ground connection. The MB power adapters up to now have always had a ground connection. The solution was simple: I replaced the plug on the new adapter (easily slides off) with one from an older adapter, and now there's no more current leakage. I can't understand why Apple ships a problematic plug with the new power adapters when they used to ship a better - grounded - cord, which is probably healthier for the Mac.

If you need a grounded connection, get the extender cable mentioned above - then you'll have a grounded connection. Far more people don't need the cable than do need the cable, so Apple quit including it some years ago. Yet it's still available for those who want/need one. Also available less expensively via third party sources.

Current leakage isn't a problem for most people -- since typically there's minimal neutral to ground voltage on most household circuits. Sounds like you may have a wiring issue at that outlet to get checked out if you're getting enough voltage on the neutral circuit to notice.

Oh and - the computer doesn't care - the adapter will convert a range of hot-to-neutral voltages to the appropriate voltage for the computer.
[automerge]1594037615[/automerge]
We also had the earth/ground connection tested at the main fuse box and that came back as working as it should be.
Need to check the neutral to ground voltage at the suspect outlets.

Checking it at the fuse box doesn't really address the possibility of issues in the neutral wiring between the outlets and the fuse box.
 
Comment

NewBench

macrumors regular
Original poster
Jun 24, 2010
231
172
UPDATE!

Stupidly when I got back I realised the whole time I was wearing shoes when plugging my MBP into the socket in the other house so was unknowingly grounding myself the whole time.

Took them off, and had the same buzzing sensation with my MBP. Whatever the issue is, it isn't down to a fault with the MBA or MBP.

Issue solved by using an extension socket.
 
Comment

Mopar

macrumors regular
Feb 24, 2011
122
127
I think this happens when using an ungrounded charger, extension cord or electrical outlet. This happens with any devices that have metal surfaces. If the entire "chain" is grounded you won't feel that vibrating when touching the surface of the device.
This is correct. We have had this issue with pretty much all the Mac laptops shipped in Australia with two-pin connectors. As soon as you add an earth-wire extension cable (pictured), the issue disappears. I can replicate this problem on every laptop we own: 2013 MBA, 2016 MBP, 2020 MBA etc

While it has been noted that the plug end has an earth wire and the adapter end does not, in fact there is an earth at the adapter end which is the metal nub inside the slider.

 
Comment
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.