electric shock on 220V net

While I may not have been using 220v, using standard 110v here in the States, but did encounter the same thing while using the two prong adapter and not the three prong grounded cable that you can attach to the power supply. I got the same weird electrical "vibe" passing through the palm rest. Definitely some sort of ground problem.

It may depend on where you went. Some countries standards for grounding and safety are, well, none existent. I also was in a country with 220v and the plug ins were only 2 prong so I had no choice. I was lucky in that there were no problems...

It may depend on where you went. Some countries
standards for grounding and safety are, well, none
existent.

Peter, that may be true, but when I look at the recessed plugs used in many of those countries I see it being evidence of forethought in design, in stark contrast to the ridiculous ones we use here.

Either way, 110 or 220, feeling electrical current passing through your body is a disconcerting experience to say the least. I for one don't think anyone can afford a full body recall.

I can agree to a point. Where I was, the plugs were a combo US/Euro design. The switches were better quality too. This was the Philippines. However, the wiring behind the walls you cannot see.

I don't discount your problem

I presume you are using the Apple 85W adapter with your MacBook Pro? My adapter (I live in Europe) came with both the earthed german "Shuko" power plug and the not-earth-enabled generic EU 2-pin plug.

When you use a power adapter with a non-earthed plug or mains socket (not just Apple but many of my "Double Insulated" IT/Infotainment systems) the equipment case will tend to float at half of the supply voltage. With 220V supply this therefore gives a case voltage of 110V. The voltage is clearly perceptible but the available current is tiny, often in the range of 10 microamps to one milliamp and is due to leakage effects through qualified components. It can give from a 'slight tickle' to a 'light-bite' with damp hands, and has the interesting effect of a feeling of bouncy vibrations when the back of the hand is lightly stroked over the equipment case.

If there is no supply adapter fault, then the leakage situation is mostly safe, but could cause audio/video hum, possible accessory device damage and should be considered as a mild hazard.

In the US, the same leakage will occur, but the voltage would be a nice low "half of 110V" which is within the Telecommunications Industry Human Safe Voltage area of max 48 to 72 volts to be available at customer terminal equipment! the (leakage) current should be less than 30 milliamps.

it's the Volts that Jolts, but it's the 'mills that Kills!



many Macs 512k -> MacBool Pro 2GHz 1GB ram Mac OS X (10.4.7) Yes, I have Key Lime

Recently I traveled to a country with 220V
electricity instead of 110V in the US. I noted that
when the charger was plucked in a electric current
was palpable on the handrest areas next to the built
in mouse.

Anybody have the same experience?

Yes, I can also feel it over the speaker covers and on the lid esp. around the logo.

I've been living in Thailand for the past 19 years and I get the same stacic discharge off our Air/con which has an Aluminum case. Here we use 220v/50Hz, as apposed to 110v/60Hz in the US. I had a heck of a time trying to get full power out of our microwave we brought over because of the difference in A/C cycles (50Hz/60Hz). They've just recently made it an electrical standard to use three pronged plugs, but many times I still see electricans cut/yank the thrid prong off to accomodate an older socket!

Since the current (amperage) is so low, it's not considered dangerous, but like any electrical appliance, I wouldn't use it in the bath or in the rain. 😉 The three pronged adaptor will take care of most, if not all of the problem.

Chakris

it's the Volts that Jolts, but it's the 'mills that
Kills!

LOL!... Now thats funny! Gotta remember that one.

Having used iBooks that would explain everything you mentioned because the plastic didn't "conduct" any current. Everything you mentioned, and this would be with the two prong, I've experienced. Thankfully at a low level.

On something like this, would a simple test with a meter testing the case of the MPB reveal any "leakage"? In my case I cannot distinguish if the feeling is electric or a fine vibration from the HD. It is probably electric after thinking thru all of this.

The electrical effect feels sort of like a fine fuzz on the case-- you move your fingers over the metal and you feel fuzz at your finger tips. These are like little sparks jumping to your fingers. A good voltmeter may show maybe 50 or 100 volts between you and the case. A cheaper meter may not show anything at all. The non-loaded potential difference is probably even larger.

This feels funny as long as there are little gaps between your fingers and the case to allow the sparks. But as soon as you touch the case firmly the voltage difference drops to zero and the current is in billionths of an amp.

I have on occasion independently grounded my case to prevent the little shocks.

I wonder if the 7200rpm HD (which I have) is mounted in such a way that the very fine vibration transmits though the case. I don't feel much on top but if I touch the sides of the case I feel it. It does almost feel like electricity at a low voltage. However, I can lay my hand on the desk just to the left of the computer and feel the vibration there. (cheap desk).

I've felt it a couple of times too (I'm in the US).

My solution has been to plug in the extension cable that came with the adapter. That has a ground prong (the adapter doesn't), which is probably what's fixing it.