4 ms·

You either have a bad supply or a floating earth, that is cuased by a bias between earth and tbe floating earth on the laptop. Put a multimeter between the eart

You either have a bad supply or a floating earth, that is cuased by a bias between earth and tbe floating earth on the laptop. Put a multimeter between the earth pin on your supply and the body of the laptop and if you put it into ac volts mode you can see it. This is NOT static, its is A/C volts on your device.

petronic 8y ago
It's apparently a known phenomenon called "electrovibration" - I wound up googling it the first time that it happened. https://blog.somaticlabs.io/electrovibration-in-ungrounded-macbook-pros/ https://blog.somaticlabs.io/electrovibration-in-ungrounded-m...
- Reason077 8y ago
  My old MacBook Air did this a lot! My 2017 13" MacBook Pro does it too, but it's intermittent and much less noticeable. In both cases it completely disappears if you unplug the AC.
  - deleted 8y ago
    [deleted]
  - LyndsySimon 8y ago
    Ditto. I had a late-2013 15” MBP that did it consistently, and it was worse when you touched the bottom of the chassis. My mid-2015 MBP did it slightly, and I’ve not detected it on my current-gen 13” MBP or any of my non-Apple hardware.
    - Reason077 8y ago
      It's noticeable on my 13" 2017 non-touchbar MacBook Pro, but only when you run your fingers along the part of the case above the keyboard. It was much more noticeable on the MacBook Air, with pretty much the entire aluminium surface of the case having the issue.
  - ksec 8y ago
    I didn't notice it when I had the 2017 Macbook, but both my Macbook Air and MBP 2015 has the same issue. Why hasnt Apple solve this after all these years? Edit, I am using it with the UK plug, unsure how this is a grounding issue.
    - Reason077 8y ago
      I'm pretty sure the UK MacBook charger plug is not grounded. It has the ground pin, of course (UK sockets won't accept a plug without it), but there's only the standard 2 wires going from the detachable plug to the main body of the charger.

petronic 8y ago

It's apparently a known phenomenon called "electrovibration" - I wound up googling it the first time that it happened. https://blog.somaticlabs.io/electrovibration-in-ungrounded-macbook-pros/ https://blog.somaticlabs.io/electrovibration-in-ungrounded-m...

Reason077 8y ago
My old MacBook Air did this a lot! My 2017 13" MacBook Pro does it too, but it's intermittent and much less noticeable. In both cases it completely disappears if you unplug the AC.
- deleted 8y ago
  [deleted]
- LyndsySimon 8y ago
  Ditto. I had a late-2013 15” MBP that did it consistently, and it was worse when you touched the bottom of the chassis. My mid-2015 MBP did it slightly, and I’ve not detected it on my current-gen 13” MBP or any of my non-Apple hardware.
  - Reason077 8y ago
    It's noticeable on my 13" 2017 non-touchbar MacBook Pro, but only when you run your fingers along the part of the case above the keyboard. It was much more noticeable on the MacBook Air, with pretty much the entire aluminium surface of the case having the issue.
- ksec 8y ago
  I didn't notice it when I had the 2017 Macbook, but both my Macbook Air and MBP 2015 has the same issue. Why hasnt Apple solve this after all these years? Edit, I am using it with the UK plug, unsure how this is a grounding issue.
  - Reason077 8y ago
    I'm pretty sure the UK MacBook charger plug is not grounded. It has the ground pin, of course (UK sockets won't accept a plug without it), but there's only the standard 2 wires going from the detachable plug to the main body of the charger.