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Comment by smnscu | Hacker News Reader

(slightly off-topic) Am I the only one who notices the static(?) happening when Macbooks are plugged in? Symptom 1, brushing your hand against the aluminium feels weird, this doesn't happen when you remove the charging cable. Symptom 2, back when I used wired headphones I could clearly distinguish the static noise when the system was plugged in, it would go away if I touched the laptop or, again, remove the charging cable.

edit: I'm in Tunisia right now, and every socket here seems to have the 3rd prong thingie which I can only assume it's the ground connection. So I can confirm petronic's account, no symptoms here whatsoever.

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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.

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-m...

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.

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.

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.

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.

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.

You have grounding issues. Stop whatever you're doing and get an isolation transformer. On the off chance that that isn't clear: NOT a moving transformer or 'auto' transformer they have only one coil, you want one with a primary and a secondary winding that are galvanically isolated, but with an equal number of windings (so the voltage doesn't change).

And stay away from any metal and tubing in the place where you are (heating, concrete rebar, water lines).

I've noticed #1 when traveling with the ungrounded attachment for the power brick and a type-F power adapter. At home I still use the old 3-prong cable from my previous gen MBP or USB-C power from a dock's grounded power supply and don't get that weird sensation.

I have this problem often when I’m in Africa. Sometimes the case shocks me very lightly as well. I’ve always assumed it’s a problem with lack of grounding and/or dirty power. (Had it with non-macs as well)

Holy shit, I completely forgot. But yes, I've had this happen to me as well. It's a bit... distressing to get (slightly) shocked by your laptop.

Yes, I'm in South Africa right now and this issue is very frequent. It helps some to use the two-prong plug on the charger instead of the three-prong plug. (If anyone can explain why that works, I'd love to know.)

This is very common, it happens when the power connection isn't grounded. I've had it with all my aluminum macbooks going back to 2010, no damage so far.

Are you talking about one specific unit? That reads more like you have a insulation/isolation/grounding failure. Parts of the system and chassis are energized, where they should not be.

I'd look into this ASAP.

Nope, at least 3 different macbooks, different models/years. Check out the replies in the thread, especially the thread linked by et-al.

Have a business associate who was debating between a 2015 and a 2016 model, while both were being sold by Apple.

I've been meaning to tell him just how much he dodged a bullet, by going with the 2015.

P.S. I see now, this problem pre-dates the 2016 models.

Still think -- keyboard failures, etc. -- he dodged a bullet.

But this behavior -- well, it would freak me out a little.

Yup, you're not a alone: https://news.ycombinator.com/item?id=12946673

I definitely notice (1) from time to time.

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