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How can I avoid my MacBook Pro giving me minor shocks?

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Re: How can I avoid my MacBook Pro giving me minor shocks?

#111

Post by phee »

Animats wrote: post #110

Doesn't anybody have a DVM around? If you can feel a stray voltage, measure it, and find the source. As someone else pointed out, get an outlet tester.[1] They're about $7. You may have an open ground, or reversed hot/neutral. Once you've eliminated that, suspect the power supply. Make sure you have a UL-listed power supply. If you're getting stray AC voltage on the output side of a UL-listed supply, report it to UL.…

About reversed hot/neutral. We have these[1] symmetrical adapters in Europe. How are you supposed to know the proper orientation? You are not. Because you either have an earthed metal case or you have a double insulated device.

My magsafe adapters have a "double insulation" symbol, a tiny tiny one near "UL Japan", but still need a earthed prong to not feel any shock from the laptop metal case.

1. http://images.apple.com/support/assets/images/products/ac-wa...

Re: How can I avoid my MacBook Pro giving me minor shocks?

#112

Post by algesten »

kosma wrote: post #23
ars wrote: post #15

Earlier quoted context omitted.

The 70v is probably induced voltage at milliamp levels. You can fix it by bonding the neutral to ground at the breaker box.

This is potentially deadly advice. A neutral/grounding fault will energize all your home devices with live potential; same with a live/neutral swap (unlikely but possible with Indian wiring standards).

Yes. In my previous place in India the RCD was repeatedly tripping up.

Earth here was a metal rod into the ground, and I only found out much later they fixed the RCD issue by disconnecting the rod and I started getting electric shocks from touching my fridge while my crappy toaster was connected.

That's when I decided to not mess with electrics in India. It's dangerous enough as it is.

As for the 70V, I eventually managed to reach someone in the electrics company that understood my issue, and they told me a local transformer for the whole street was broken. And they didn't have any plan to fix it.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#113

Post by nicky0 »

stillworks wrote: post #95
sfifs wrote: post #3

Don't use Macs but I'm surprised Apple apparently didn't give an earthed power adapter by default on a metal skin product. This seems like negligence. Now that I think about it, my iPad's the same when charging.

In the U.K. they come with earthed plug. However I still noticed "buzzing" in the MBP, MBA and even iPad when I would touched them. Took the MBP in to the store. It didn't buzz there. They gave me a new power supply anyways and recommended I connect the plug directly into the wall socket. Turned out that the power strip I was using is not grounded even though it has three pin sockets ! When I plug Apple devices direc…

Throw away that power strip.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#115

Post by jmmcd »

phee wrote: post #103
stouset wrote: post #79

Earlier quoted context omitted.

I'm deeply curious about this! Is it possible to recreate the situation at home, or does this require something miswired with the mains power supply or power adapter, or an older MacBook Pro?

connect the two prong adapter, take your shoes and socks off, feet on the ground... feel the vibe! the best shocks you get at the edges or at the pointy edges in that groove to lift the display up.

> feel the vibe! the best shocks [...]

Users enjoying electric shocks. Reality distortion field operating at nominal.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#116

Post by mnw21cam »

nicky0 wrote: post #113
stillworks wrote: post #95

Earlier quoted context omitted.

In the U.K. they come with earthed plug. However I still noticed "buzzing" in the MBP, MBA and even iPad when I would touched them. Took the MBP in to the store. It didn't buzz there. They gave me a new power supply anyways and recommended I connect the plug directly into the wall socket. Turned out that the power strip I was using is not grounded even though it has three pin sockets ! When I plug Apple devices direc…

Throw away that power strip.

As in, right now. It violates every electric safety law around.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#117

Post by elcct »

nicky0 wrote: post #113
stillworks wrote: post #95

Earlier quoted context omitted.

In the U.K. they come with earthed plug. However I still noticed "buzzing" in the MBP, MBA and even iPad when I would touched them. Took the MBP in to the store. It didn't buzz there. They gave me a new power supply anyways and recommended I connect the plug directly into the wall socket. Turned out that the power strip I was using is not grounded even though it has three pin sockets ! When I plug Apple devices direc…

Throw away that power strip.

I would rather at least try to disassemble it before throwing away - otherwise it is likely that someone will pull it from the bin and use it or sell it.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#119

Post by mnw21cam »

xenadu02 wrote: post #28
burger_moon wrote: post #10

Earlier quoted context omitted.

I get it in my apartment (I live in the U.S.) which is brand new with 3 prong sockets if I have my feet on the ground (concrete floor) while roughing the laptop. I've experienced it a few more times at different peoples houses as well.

You might buy an outlet tester and see if your hot/neutral are reversed or if ground isn't connected. If it all checks out you can use a multimeter* to check potential between neutral and ground. If your apartment is wired correctly there should be almost no voltage between the two. At the breaker box the neutral and ground are supposed to be bonded together. That means only minor induced charges inside the building…

> At the breaker box the neutral and ground are supposed to be bonded together.

Note this advice is country-specific. In some countries, the bonding is done further away from the house.

In any case, you should never trust the neutral line to be an earth. If a fault occurs that disconnects the neutral line from the supply, your neutral line will have deadly voltage on it by virtue of being connected to live through your appliances. Moreover, depending on the multimeter you use, if you measure the voltage between neutral and earth, you could possibly trip the RCD in the distribution unit (if you have one).

The rules are simple in most countries - if it has any touchable metal parts, it must be earthed.

Re: How can I avoid my MacBook Pro giving me minor shocks?

#120

Post by phee »

jmmcd wrote: post #115
phee wrote: post #103

Earlier quoted context omitted.

connect the two prong adapter, take your shoes and socks off, feet on the ground... feel the vibe! the best shocks you get at the edges or at the pointy edges in that groove to lift the display up.

> feel the vibe! the best shocks [...] Users enjoying electric shocks. Reality distortion field operating at nominal.

right, it's so powerful it's also interfering with your sarchasm detector, apparently.
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