3 ms·

> It's easy for me to feel the mains frequency while gently rubbing the top surface of the MacBook I haven't been a regular Mac user, but I've had maybe 3 work

> It's easy for me to feel the mains frequency while gently rubbing the top surface of the MacBook I haven't been a regular Mac user, but I've had maybe 3 work MacBooks since 2010 and I recall having this issue with all of them. Why haven't they fixed it?

msephton 6mo ago
It's also an issue on the new Neo. It was the first thing I noticed when I tried one in the Apple Store. I unplugged the power cable and it went away, replugged and it came back. I'm in the UK so I expected grounded electricity supply.
- normie3000 6mo ago
  Disappointing. I understood Neo doesn't come with a power plug in UK; was yours the official one?
  - msephton 6mo ago
    It was just me trying one in the Apple Store
- SeasonalEnnui 6mo ago
  If you buy the UK 1.8-metre Power Adapter Extension Cable, this has a metal ground pin that grounds through the metal clip on the power brick. I switched all my MacBook & iPad chargers to this, no more earth leakage sensation from metal casing.
sitharus 6mo ago
They can’t, it’s caused by the capacitors required to suppress electromagnetic interference caused by the switch-mode power supply. These allow a very very tiny amount of current to leak through from the mains side, which is then capacitively coupled to the metal case (IIRC Apple do not connect the case to power negative) reducing it further, but it’s enough for humans to sense it. It can be avoided by using a grounded power supply, but because there are large countries that have ungrounded outlets in common use the most designs are ungrounded.
- robotbikes 6mo ago
  I once had an HP with an aluminum case and it had a grounded power supply but if you plugged it in without grounding his an adapter (sometimes you gotta do what you gotta do). You could feel it straight up vibrate while conducting current if you rubbed your hand over it. Not enough to shock me but it felt like kind of a shoddy design and leaked a lot more current than I've felt on a MacBook.
  - ebbi 6mo ago
    Is that what it is! On my pre-unibody MBP I used to run my finger across the body sometimes and it had this weird wavy feeling (honestly can't describe it well). I thought it was just a quirk of the aluminium itself!
- ranger207 6mo ago
  Why do only Macbooks suffer from this problem? When I had a work-issued Macbook I charged it and my personal Framework off the same USB-C charger and I only every felt the leaking current from the Macbook
  - numpad0 6mo ago
    Only Apple is insane enough to make actual laptop chassis with unpainted anodized aluminum. Others either do it in plastics and/or painted metal. And paints are kind of liquid plastics.
  - normie3000 6mo ago
    Additional question: why do only some people notice?
    - sitharus 6mo ago
      It’ll depend on how well grounded you are compared to how well grounded the laptop is, where it’s touching your body, and your sensitivity to electricity which varies.
  - 6mo ago
throwaway290 6mo ago
You wouldn't have this if your plug was properly grounded. Most developed countries have plugs that have grounding. EU via side pins UK via third prong
- p_l 6mo ago
  Apple avoids shipping grounded plugs as if it was personal affront to Ive. Also caused many many times for me to be shocked with electrostatic build-up.
  - throwaway290 6mo ago
    all my EU/UK macbook plugs I got from apple are always grounded, metal prong and metal side pins so what I mean is maybe house electricity grid is not grounded.
    - swiftcoder 6mo ago
      > all my EU/UK macbook plugs I got from apple are always grounded, metal prong and metal side pins The short version, where you remove the extension with the 3-prong plug and attach the plug directly to the charger brick, is only available in 2-prong in the EU/US (the UK thankfully still gets all 3 prongs in this configuration)
      - throwaway290 6mo ago
        yes true the short one has no grounding. Anyway as I replied to the other guy (and got downvoted for it) if the plug was grounded there would be no issue. Apple chargers have ground pins. But sure it's bad if they stopped including grounded versions by default in EU...
        swiftcoder 6mo ago
        I really wish some 3rd party would build a 3-prong plug adapter for the EU
erincandescent 6mo ago
You can fix it by switching to one of the grounded charger heads. Unfortunately in most locales those are only available with an integrated extension cable (or as everyone seems to call them, the "gooseneck" cables) It happens with other 2-pin chargers on both MacBooks and other laptops, but it depends upon various factors how strong the leakage is

msephton 6mo ago

It's also an issue on the new Neo. It was the first thing I noticed when I tried one in the Apple Store. I unplugged the power cable and it went away, replugged and it came back. I'm in the UK so I expected grounded electricity supply.

normie3000 6mo ago
Disappointing. I understood Neo doesn't come with a power plug in UK; was yours the official one?
- msephton 6mo ago
  It was just me trying one in the Apple Store
SeasonalEnnui 6mo ago
If you buy the UK 1.8-metre Power Adapter Extension Cable, this has a metal ground pin that grounds through the metal clip on the power brick. I switched all my MacBook & iPad chargers to this, no more earth leakage sensation from metal casing.

sitharus 6mo ago

They can’t, it’s caused by the capacitors required to suppress electromagnetic interference caused by the switch-mode power supply. These allow a very very tiny amount of current to leak through from the mains side, which is then capacitively coupled to the metal case (IIRC Apple do not connect the case to power negative) reducing it further, but it’s enough for humans to sense it. It can be avoided by using a grounded power supply, but because there are large countries that have ungrounded outlets in common use the most designs are ungrounded.

robotbikes 6mo ago
I once had an HP with an aluminum case and it had a grounded power supply but if you plugged it in without grounding his an adapter (sometimes you gotta do what you gotta do). You could feel it straight up vibrate while conducting current if you rubbed your hand over it. Not enough to shock me but it felt like kind of a shoddy design and leaked a lot more current than I've felt on a MacBook.
- ebbi 6mo ago
  Is that what it is! On my pre-unibody MBP I used to run my finger across the body sometimes and it had this weird wavy feeling (honestly can't describe it well). I thought it was just a quirk of the aluminium itself!
ranger207 6mo ago
Why do only Macbooks suffer from this problem? When I had a work-issued Macbook I charged it and my personal Framework off the same USB-C charger and I only every felt the leaking current from the Macbook
- numpad0 6mo ago
  Only Apple is insane enough to make actual laptop chassis with unpainted anodized aluminum. Others either do it in plastics and/or painted metal. And paints are kind of liquid plastics.
- normie3000 6mo ago
  Additional question: why do only some people notice?
  - sitharus 6mo ago
    It’ll depend on how well grounded you are compared to how well grounded the laptop is, where it’s touching your body, and your sensitivity to electricity which varies.
- 6mo ago

throwaway290 6mo ago

You wouldn't have this if your plug was properly grounded. Most developed countries have plugs that have grounding. EU via side pins UK via third prong

p_l 6mo ago
Apple avoids shipping grounded plugs as if it was personal affront to Ive. Also caused many many times for me to be shocked with electrostatic build-up.
- throwaway290 6mo ago
  all my EU/UK macbook plugs I got from apple are always grounded, metal prong and metal side pins so what I mean is maybe house electricity grid is not grounded.
  - swiftcoder 6mo ago
    > all my EU/UK macbook plugs I got from apple are always grounded, metal prong and metal side pins The short version, where you remove the extension with the 3-prong plug and attach the plug directly to the charger brick, is only available in 2-prong in the EU/US (the UK thankfully still gets all 3 prongs in this configuration)
    - throwaway290 6mo ago
      yes true the short one has no grounding. Anyway as I replied to the other guy (and got downvoted for it) if the plug was grounded there would be no issue. Apple chargers have ground pins. But sure it's bad if they stopped including grounded versions by default in EU...
      - swiftcoder 6mo ago
        I really wish some 3rd party would build a 3-prong plug adapter for the EU

erincandescent 6mo ago

You can fix it by switching to one of the grounded charger heads. Unfortunately in most locales those are only available with an integrated extension cable (or as everyone seems to call them, the "gooseneck" cables) It happens with other 2-pin chargers on both MacBooks and other laptops, but it depends upon various factors how strong the leakage is