MacBooks "buzzing/pulsating" whilst charging.

[Alpha Centauri]

My 2009 MBP does this quite strongly. It‘s not a burst of static discharge, especially when ambient air is dry. This is a continuous buzzing when moving one’s hand across the case. My m2 MBP doesn’t do this at all.

So I’m a fan of Hannah Fry and her practical explanations of physics, and came across this brilliant take of what’s really going on when this happens. Pls take a look of the link before commenting:

 

[Alameda]

If you plug your Mac charger into the wall using a grounded, three-prong plug, then you don't get the buzz. Apple used to include this cable with Macs but they no longer do.

 

[Alpha Centauri]

If you plug your Mac charger into the wall using a grounded, three-prong plug, then you don't get the buzz. Apple used to include this cable with Macs but they no longer do.

I bought the 2009 and 2023 MBP outside of Europe so got some Type-C Europlugs.

Interestingly enough the 2009er has the AC cord that is indeed earthed but displays that "vibrating" sensation.

My 2023 however has no seperate ground as it’s the Apple travel adapter but doesn’t have this phenomenon.

Perhaps there’s an issue with the charging circuit on this 17 yr old machine, or just maybe the fact the batteries health being at 30%.

 

[Alameda]

I bought the 2009 and 2023 MBP outside of Europe so got some Type-C Europlugs.

Interestingly enough the 2009er has the AC cord that is indeed earthed but displays that "vibrating" sensation.

My 2023 however has no seperate ground as it’s the Apple travel adapter but doesn’t have this phenomenon.

Perhaps there’s an issue with the charging circuit on this 17 yr old machine, or just maybe the fact the batteries health being at 30%.

The outlet must be three prong grounded as well.

Then again, I haven’t tried this on every MacBook model so maybe some are different than others. I don’t know.

 

[tarsins]

All my past MacBooks have done this (in the UK).

 

[dblissmn]

No such buzz here. M1 Max and M5 Max MBP's with NEMA three-prong plug on 120 volts. There may be the faintest hint of a hum if I place my right ear right on the keyboard of the M5 Max, but my left ear which has a bit of high-frequency sound damage doesn't pick it up. It's nothing like the CoreDuo or even Core2Duo.

I have not tried things out with the two prong plug directly on the adapter.

 

[Alameda]

No such buzz here. M1 Max and M5 Max MBP's with NEMA three-prong plug on 120 volts. There may be the faintest hint of a hum if I place my right ear right on the keyboard of the M5 Max, but my left ear which has a bit of high-frequency sound damage doesn't pick it up. It's nothing like the CoreDuo or even Core2Duo.

I have not tried things out with the two prong plug directly on the adapter.

Right, but with a 2 prong plug there will be. It’s not a buzz, it’s a sensation you can feel on your skin. Kinda cool.

 

[Alpha Centauri]

The outlet must be three prong grounded as well.

Then again, I haven’t tried this on every MacBook model so maybe some are different than others. I don’t know.

And there in lies the conundrum. My M2 has never done it and power runs through an Apple AC travel adapter that is only 2 pronged.

The 2009er has indeed the earth rails on the adapter. I mean its always tried to electrocute me upon contact but it sits on synthetic blankets, there’s carpet also and dry heat during winter…I say fair enough on that count.

On reflection it only started this buzzing/ tingling sensation in the last year (out of 17). So that’s why I’m thinking either the charging brick has had it (been through a few) , or the battery’s (been through many) 30% health is causing it.

 

[Alpha Centauri]

Right, but with a 2 prong plug there will be. It’s not a buzz, it’s a sensation you can feel on your skin. Kinda cool.

Absolutely hard to describe, isn’t it. That’s why I was happy with myself to find that video in my OP.

No such buzz here. M1 Max and M5 Max MBP's with NEMA three-prong plug on 120 volts. There may be the faintest hint of a hum if I place my right ear right on the keyboard of the M5 Max, but my left ear which has a bit of high-frequency sound damage doesn't pick it up. It's nothing like the CoreDuo or even Core2Duo.

I have not tried things out with the two prong plug directly on the adapter.

yes it’s my 3 pronged C2D that’s telling this story. Mine actually never had a hum of sorts.

It did have everything else including few component level logic board repairs, many many Super Drives and as many batteries, speakers/ subwoofers and screens.

It’s actual a Frankenstein to the point that the 3rd party insurer released themselves from the contract, due to them losing money on this device.

 

[Alpha Centauri]

All my past MacBooks have done this (in the UK).

Interesting. I’ve only a study/ comparison of 2 MBP’s with a 14 yr age gap between them. The M2 has in 3 1/2 yrs not once exhibited this behaviour. The offending C2D only began with this after 16 yrs.