[Kadarin]

Here's an odd one: When I'm at work, if I have the MBP plugged in using the direct plug attachment for the adapter brick, I hear static on my Avaya ip phone when I'm on a call, whenever I touch the MBP casing. I don't notice this when the adapter is plugged into the extension cord, which in turn is plugged into a three-pronged socket. The static is enough to drown out the call, and others on the call noticed it.

Anyone else notice this?

[Simon]

This is a well known problem and it has been discussed several times on this bord.

The extension cord grounds the adapter and hence the MBP. The direct plug ('duck bill') doesn't connect the ground. Use the extension cord if you're experiencing static, ground loops, etc. If somebody experiences problems even when using the extension cord, chances are the ground wiring is faulty.

[ghporter]

When you touch the MBP, you're acting as an antenna for the internally generated radio signals-which would be completely contained if the case were grounded, as with the three-prong extension cord. Two solutions present themselves: use the extension cord, as Simon suggests, and don't touch the MBP while using your phone (maybe by using some insulating material such as a towel or newspaper on the palmrests if you really need to use the computer).

[Kadarin]

Thanks for the confirmation, guys. I'm fairly new to this board, so haven't noticed the topic before.

[ghporter]

Usually it's from the context of "I got a shock from my computer!!!". Again, this is because the two-prong adapter on the power supply doesn't ground anything and sometimes - nowhere near even "frequently" - a difference of potential builds up in the case of the computer. Nothing to worry about, just a discomfort. Oh, and no matter what anyone says, it ain't "static" electricity that's giving them the shocks.