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greentint

macrumors newbie
Original poster
Jan 30, 2022
13
3
Hey everyone.
Recently got a MBA M1 and noticed something weird. When the laptop is charging and when I plug in my external monitor to my Mac (using a Display Port to USB-C adapter) , if i run a finger on the back of the laptop lid, I feel a slight electric vibration. The charger is the original 30 Watt charger that comes in the box. Coincidentally, I tried charging my Macbook in another room with a Dell USB-C charger, and in this case did not get that vibration. Overall I am curious if this can damage the Macbook, as I have to use the external monitor for my work.
I appreciate any help and suggestions.
Thank you all very much.
 

doolar

macrumors 6502a
Nov 25, 2019
644
1,128
It's because the power brick lacks the earth prong on the connector. Back in the good old days all Macbooks came with the extension cord, and that's got the ground connector - the power bricks have the connector too.

Now this won't help in your specific case, but if you use a charger with a ground connection to a grounded wall socket, you won't be grounding the computer with your hands - and the tingling will stop.

Here's the cable I mean if you've not seen it before. I use my old trusty one from an older Macbook, and I think you can buy them from Apple directly:

s-l640.jpg
 

greentint

macrumors newbie
Original poster
Jan 30, 2022
13
3
It's because the power brick lacks the earth prong on the connector. Back in the good old days all Macbooks came with the extension cord, and that's got the ground connector - the power bricks have the connector too.

Now this won't help in your specific case, but if you use a charger with a ground connection to a grounded wall socket, you won't be grounding the computer with your hands - and the tingling will stop.

Here's the cable I mean if you've not seen it before. I use my old trusty one from an older Macbook, and I think you can buy them from Apple directly:

s-l640.jpg
ok that explains that, but why is it happening while my monitor is connected though ?
 

greentint

macrumors newbie
Original poster
Jan 30, 2022
13
3
I am wondering if the vibration caused by the monitor is due to a bad usb-c dongle ?
 
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