[FlammableYurt]

A couple years ago I used my old macbook pro in the caribbean islands using a power adapter (the standard there is round socket). I noticed that my laptop would occasionally start to vibrate subtly, so that you could feel it but not see or hear it.

Now I'm abroad again, and I'm going to be here for some time, and the same thing is happening with my new macbook pro. The sockets here are for the most part the same as those I used in the caribbean.

So first of all, I'd like to know if this is something I should worry about, or if it's harmless. If it's bad, I'd like to know if there's anything I can do about it... I've noticed that none of the adapters I've seen have a spot for the grounding pin, maybe that has something to do with it? I know the voltage and frequency here are different than in the states, but according to the specs on the charger it should be able to handle that.

Any advice?

[Simon]

It's likely a lack of proper grounding. The "vibrating" you sense could be trickle currents running through the case.

Make sure you use properly grounded sockets and make sure your adapter passes the ground through. Many adapters (especially the cheap ones) don't.

[FlammableYurt]

Thanks for the response! Most of the sockets here only have two contacts - is there even a way to pass ground through one of those?

[analogika]

No.

This is the issue you're experiencing:
http://forums.macnn.com/69/mac-noteb...lectric-shock/
click for lengthy explanation/discussion.

[Simon]

Originally Posted by FlammableYurt 

Thanks for the response! Most of the sockets here only have two contacts - is there even a way to pass ground through one of those?

No, but some adapter plugs pass ground to an external lead. Connect that to your plumbing (or any other grounded conductor in hour household) and you should be fine too.


The ground lead is that little metal clip with the hole in the right picture.

[FlammableYurt]

Thanks for all the help and explanations! I'll go out tomorrow and look for a better adapter.