[automated_workflows]

I keep getting electric shocks from my macbook pro casing whenever the machine is bein charged up. now when the battery is charging, i cant rest my hands on the metal at all or i will get a shock. Is it only my unit or anyone else getting it?

[Mithras]

Umm take that back to Apple. No, the rest of us do not get electric shocks.

[skyman]

Originally Posted by feynman82

I keep getting electric shocks from my macbook pro casing whenever the machine is bein charged up. now when the battery is charging, i cant rest my hands on the metal at all or i will get a shock. Is it only my unit or anyone else getting it?

Show us a picture of your MacBookPro?

[seanc]

Are you near any tv's or anything static? Whenever I put my foot near my tv, I get a shock off anything metal but mainly the latch button on my iBook.

[f1000]

I've occasionally felt an AC buzz on both the Rev A and Rev B 12" PowerBooks, and I think the sensation is more noticeable around the sharp aluminum edges of the trackpad/button where the anodization is thinner or has worn off.

The power entering your laptop is only a few volts at a few tens/hundreds of milliamps, so you're not going to get electrocuted due to a ground fault. In fact, this is why PowerBooks don't require a ground plug.

[romeosc]

Check it with a different ac outlet! Your outlet may have been wired incorrectly.... Hot on neutral!

If you have a outlet tester, it will show incorrectly wired outlet or a floating ground. Very dangerous to you and your equiptment. I know the computer adaper converts AC to DC, but an outlet wired improperly can cause AC hum or mild grounding feeling.

[analogika]

There's a 115 volt AC current on the casing of all aluminum 'books when you're not using the three-pronged grounded power cable.

This, according to AppleCare support, is entirely within spec.

I called them because my $2,500 Firewire audio interface would spark every time I hooked it up to my 12" Powerbook, as would all my Firewire hard drives and powered USB devices.

They suggested using the grounded extension cord instead of the little two-pronged corner thingie.

[f1000]

Originally Posted by analogika

There's a 115 volt AC current on the casing of all aluminum 'books when you're not using the three-pronged grounded power cable.

At most, I get a reading of about 40-60 volts AC with my multimeter and I can't pick up a current at all. Granted, I don't have a good reference ground, but I'd be surprised if the voltage was actually 115 V.

[cgc]

Originally Posted by F1000

The power entering your laptop is only a few volts at a few tens/hundreds of milliamps, so you're not going to get electrocuted due to a ground fault. In fact, this is why PowerBooks don't require a ground plug.

I remember reading in one of my technical manuals that current values far less than you specify can kill. I don't have my books with me but here's a link that states what I've read elsewhere: http://www.allaboutcircuits.com/vol_1/chpt_3/4.html

"...It has been suggested that an across-the-chest current of only 17 milliamps AC is enough to induce fibrillation in a human subject under certain conditions..."

Originally Posted by f1000

At most, I get a reading of about 40-60 volts AC with my multimeter and I can't pick up a current at all. Granted, I don't have a good reference ground, but I'd be surprised if the voltage was actually 115 V.

"Only 40-60 volts?" Since when is any volts on the case of an electronic device acceptable? I think whoever at Apple stated this was in error.

[John123]

I get shocks, just like I have with metallic 'Books since the start of time. Check for static discharge...

[MacG33k]

Originally Posted by Mithras

Umm take that back to Apple. No, the rest of us do not get electric shocks.

I get shocked from all my laptops on daily basis. I have IBM T40, PowerBook G4 1.67, MacBook Pro 2.0, and Acer TM4400.

By the way, they all equally run hot and noisy. I'm not sure what all the fuss is about. My guess is that Mac users bitch more.

[servo]

Call me crazy, but I would think any sort of electric discharge would be a bad thing with a laptop. You would be careful to be grounded when working on a desktop machine, like instaling a hard drive or RAM. Getting shocked from your laptop is okay though? That's nuts.

[f1000]

Originally Posted by cgc

"Only 40-60 volts?" Since when is any volts on the case of an electronic device acceptable? I think whoever at Apple stated this was in error.

40-60 volts AC @ microamps isn't going to kill anyone. You generate many thousands of volts just walking across a pile carpet in winter.

[f1000]

Originally Posted by servo

Call me crazy, but I would think any sort of electric discharge would be a bad thing with a laptop. You would be careful to be grounded when working on a desktop machine, like instaling a hard drive or RAM. Getting shocked from your laptop is okay though? That's nuts.

When you work inside your desktop machine, you should always unplug the power first. A grounding strap is worn to protect CMOS chips from you, not to protect you from the mains and electrocution.

[Dr.Michael]

Originally Posted by f1000

I've occasionally felt an AC buzz on both the Rev A and Rev B 12" PowerBooks, and I think the sensation is more noticeable around the sharp aluminum edges of the trackpad/button where the anodization is thinner or has worn off.

This has been discussed for the TiBooks and the Alubooks before.

The "shock" is due to an electric DISCHARGE of your body. It is worse at the edges because there the electric field is stronger. Simple, natural. It is worse with brand new units because the case is not yet covered with oxyde or other insolating/protective coatings.

If the power supply would be connected to the case, the fuse would be blown instantly.

Analogica,
do you have any reference to your statement? I am not sure, if this can be true. According to german standards, if there is any danger a metal case could be under voltage, it HAS to be grounded. If it were true, this could kill people with a cardiac pacemaker (for example).

[f1000]

Originally Posted by Dr.Michael

This has been discussed for the TiBooks and the Alubooks before.

Then you must've missed the conversation Analogika and I had concerning steady state electrical buzzing. We're talking two different issues here. Many of us have noticed a continuous electrical buzzing effect, not due to triboelectric shock, when we touch certain areas of our plugged in laptops. I have even confirmed the existence of an AC surface voltage on my PowerBook using a multimeter.

Originally Posted by Dr.Michael

Analogica,
do you have any reference to your statement? I am not sure, if this can be true. According to german standards, if there is any danger a metal case could be under voltage, it HAS to be grounded. If it were true, this could kill people with a cardiac pacemaker (for example).

After some thought, I think Analogika's claim makes sense. German voltage is 2x that of the U.S., so if you double my 40-60V measurement you get something close to 115V; nevertheless, such voltages at extremely low currents aren't going to hurt anybody.

[f1000]

The following is a quote from Macintouch:

Tim Seufert

Reader Jörg Bullmann reports getting shocked when a USB printer, scanner, or Zip drive is plugged into a 15" AlBook running off battery power. The reason for this is most likely that each of the three devices in question uses a two-prong (ungrounded) AC plug.

AC to DC power supplies output 50/60 Hz common mode ripple voltage, some more so than others. If the chassis is connected to earth ground, the ripple current is shunted directly to ground, as Jörg discovered by plugging in the AlBook's AC power supply. If there is no earth ground connection, and the user happens to touch a metal chassis grounded to the power supply, the user becomes the ground return path for the ripple voltage and mild shock results. ("Mild" here means unpleasant but probably within safe limits -- there are safety standards for how much voltage and current flow is permissible.)

To the best of my knowledge, it is standard (and good) design practice for Apple to connect the USB shield to the Powerbook's metal chassis. The computer shop guy talking about older models with worse problems was probably referring to older TiBook models which shipped with a two-prong AC power supply. In that case it was the PowerBook itself which generated the shock. Apple changed to a three-prong AC supply to eliminate the problem, but as seen here, other devices may still generate ripple that ends up on the PowerBook's shell due to the standard practice of tying shield grounds to the chassis on both ends of a cable.

[Dr.Michael]

Originally Posted by f1000

Then you must've missed the conversation Analogika and I had concerning steady state electrical buzzing.

Yes I did. I just saw this thread here. But the issue sounds exactly like the discussion about the ti and alubooks. These models had a shock effect (mine too) that vanished with time. At least this explanation has to be taken into account.

Originally Posted by f1000

We're talking two different issues here. Many of us have noticed a continuous electrical buzzing effect, not due to triboelectric shock, when we touch certain areas of our plugged in laptops. I have even confirmed the existence of an AC surface voltage on my PowerBook using a multimeter.

Interesting. Does that mean you can ground the powerbook and immediately afterwards you measure a voltage? Or does the voltage grow with time and stabilizes after a while?

Originally Posted by f1000

After some thought, I think Analogika's claim makes sense. German voltage is 2x that of the U.S., so if you double my 40-60V measurement you get something close to 115V; nevertheless, such voltages at extremely low currents aren't going to hurt anybody.

Hm, weird. To my knowledge the power supply has two disconnected circuits. The primary winding should see the plug voltage, the secondary should not be able to carry the plug voltage (or a fraction) because there shouldn't be a physical connection (only an inductive connection). Thus it is not immediatley obvious that analogica measures twice as much as you.

Well, so far the theory. The Powerbook certainly uses a stabilized eletronic power supply. Don"t ask me how this works in detail.

But it still sounds bad. I know that low voltage at low currents do not harm. Static voltage is usually a few thousand volts, thus much higher.

Don't we have any electronic engineers here, who can help with profound knowledge?

[f1000]

Originally Posted by Dr.Michael

Interesting. Does that mean you can ground the powerbook and immediately afterwards you measure a voltage? Or does the voltage grow with time and stabilizes after a while?

Yes, I can short the chassis to ground and still pick up a constant AC voltage afterwards. The potential is definitely not due to electrostatic buildup/discharge: the measured voltage is AC, after all.

Originally Posted by Dr.Michael

Hm, weird. To my knowledge the power supply has two disconnected circuits. The primary winding should see the plug voltage, the secondary should not be able to carry the plug voltage (or a fraction) because there shouldn't be a physical connection (only an inductive connection). Thus it is not immediatley obvious that analogica measures twice as much as you.

Analogika didn't measure any voltage directly. He simply restated what some service rep told him. I don't know enough to speculate on whether the potential is coming from the brick or from the PowerBook itself, though.

[Richy_Rich]

I've been having this problem.

I bought a Cooler Master Notepal to keep my macbook cool (it's metal). I realized I was only being shocked (quite seriously twice) when it was placed on the notepal.

Is anyone else recieving shocks working on a metal surface? Can anyone make sense of this?

[sllowry]

I get shocked too by my 15"MBP but only once in a while. I wonder if it's gonna cause any hardware problem in the long run though.

[primaldivine]

Originally Posted by feynman82

I keep getting electric shocks from my macbook pro casing whenever the machine is bein charged up. now when the battery is charging, i cant rest my hands on the metal at all or i will get a shock. Is it only my unit or anyone else getting it?

Nope. Apparently a number of us are experiencing this. I've been feeling a slight tingle just down from my wrists on and off for awhile now. I thought it was the hair on my arms getting caught between the metal base and the grey plastic band on the border! Today however, I had to pull my arms back suddenly. It hurt!

Some say it's due to using the adapter without the third (grounding) prong. So I took off the two prong adapter and plugged in the three prong one, and it certainly disappeared to a negligible tingle now and again.

But really, shouldn't one not have to deal with ANY shocks from one's $2500 laptop?

[eevyl]

It's not only because of the grounded prong adapter, but your wall plug must be grounded too. Sorry if it seems stupid but have to make sure this is clear.

My previous PowerBook G4 12" does get electrically fuzzy when plugged without ground, same with MacBook Pro. And that's why I always use the grounded prong and a grounded plug.

Besides not getting static, you get high degree of safety against spikes, to your health and to your electric machines. The ultimate solution is to use a good UPS to get a perfect even current flow.

[analogika]

Originally Posted by f1000

Analogika didn't measure any voltage directly. He simply restated what some service rep told him. I don't know enough to speculate on whether the potential is coming from the brick or from the PowerBook itself, though.

That is FALSE.

I measured the 115V AC on my 12" Powerbook using my trusty multimeter.

I merely received confirmation from the Apple service rep that this is entirely within spec, after having been told by an authorized tech that a large number of Titanium Powerbooks had much more pronounced cases of this than I had been experiencing.

[Zeeb]

From reading some of these posts it appears that some are confusing the shock you get from static electricity with a shock from electric current. Of course I've experienced shocks from static electricity but I have also been electrocuted and you can definately tell the difference.

If you are experiencing an actual electric shock(not static) and assuming you are using the proper power adapter and that it is plugged in correctly (as in not using any 3 prong to 2 prong adapters) I would definately be taking this computer back for replacement or repair. Don't bother measuring crap with multimeters and such. If you're getting shocked when you touch your computer do you need a multimeter to tell you that? I have a MBP and I have never once experienced a shock from it other than static.

[f1000]

Originally Posted by analogika

That is FALSE.

I measured the 115V AC on my 12" Powerbook using my trusty multimeter.

I merely received confirmation from the Apple service rep that this is entirely within spec, after having been told by an authorized tech that a large number of Titanium Powerbooks had much more pronounced cases of this than I had been experiencing.

Mea culpa; thanks for the clarification!

[d_assassin]

This is interesting! A colleague in my office gently brushed the case of my 15" MacBook Pro and said that he felt current running through the case. Two other people also agreed, although I had not felt anything. We attached a multimeter to the case of the Macbook and to earth. When the laptop in connected to the mains, we get 95 VAC on the meter. When off the mains, we got next to nothing.

When you connect the mains adaptor to the litte 3 pin adaptor thingy, that current does not have an earth pin, the voltage on the case is present. When you attach the mains cable instead, this seems to have the earth pin connected and hence, you dont get the voltge on the case!

Surely this can't be right? The adaptor states " Output 18.5v / 16.5v".

[certmagic]

i can feel an electric current when I use the direct 3 pin plug but not the 2 pin plug

[jettle250]

I was experiencing the shock when I had the 3 prong adapter plugged directly into the Power brick. The problem is now solved by using the 'extension lead' adapter (3 prong) with the Power brick.

i.e. I am now using the extension cable with my Power brick and I no longer get shocks from my MBP. Could be worth a try?

[analogika]

Originally Posted by Neub Detat

i can feel an electric current when I use the direct 3 pin plug but not the 2 pin plug

That would indicate that something isn't wired correctly within your power socket.

I'd recommend getting it checked ASAP.

[certmagic]

Originally Posted by analogika

That would indicate that something isn't wired correctly within your power socket.

I'd recommend getting it checked ASAP.

nah I wouldn't really care as much. It's probably due to the fact that I'm using one of those multi-socket adaptors on top of it as well.

It's very weird tho, and it's actually quite painful cos when I connect my firewire solo to my com and I connect my guitar to that, I get shocked when I swipe my strings with my arms.

[rhk0327]

I have a macbook pro bought refurbished about 4 months ago. Just recently I felt the electrical current when the power plug is plugged in after awhile (not with battery power). The buzz was very strong and this is definitely not right, I'm taking it in to the genius bar today. I haven't tested because I'm worrying about damaging the internal components. I'll post back.

Update: Went in to the store. I couldn't get the problem to repeat itself. They seemed clueless about it. Not wanting them messing with it, I took it back home. I resumed using it The problem didn't repeat itself for a couple days even though I tried using xbench to put the computer under strain. Then yesterday I got very minor shocking buzz after leaving it plugged in all night. Nothing compared to the first time. I'm guessing there are a lot of factors. I'm wondering if it could be a paritally faulty powersupply?

[seanc]

Well in my humble opinion, it's perfectly normal.

I've had this issue with my PowerBook, Samsung and now Dell, both at home and at college. Now I highly doubt there is anything wrong with the colleges power system because they'd be in deep s**t if there was and there's certainly nothing wrong with my laptops.

[xaoslaad]

I was getting an electric shock from my MBP and I called my wife over to try it. She wasn't getting anything. Then she pointed out that I had my foot on the computer I keep under my desk (Shuttle SB61G2) which has an aluminum case. I took my foot off, and the shocks stopped for me. Put my foot back on and they started again.

I suspect anyone getting these shocks is causing themself to be a ground like I was...

[Simon]

Were you using the three prong cable with your charger? I guess not, but if so you have faulty ground wiring.

Ideally your MBP should be grounded, but of course not by your body.

[xaoslaad]

No. I use the two prong adapter, plugged into an extension chord behind my desk. I use the three prong adapter when I travel. I don't know though; I kinda don't mind the elctro shock therapy; who knows, maybe it will help me. Kind of a free service from apple

[PaperNotes]

Fresh from the factory they all have static in them. Your body does to. Unused they build up static too and discharge when you use them again. Use the three prong adaptor and touch something metal before you use your MBP or PB. This only happens in early days. It doesn't seem to happen once a computer gets worn in. None of this is lethal and on the bright side you could evolve into an X men.

[analogika]

It is NOT STATIC and you are WRONG about the "wear-in" period, unless you are talking about many years, which I cannot verify.

Though I see it on six-year-old tiBooks, on every single demo model MacBook Pro, even after six months, and on every single customer machine.

My old Powerbook (passed on to a friend) is now three years old, and it's still got current on the case.

I suggest you re-read the thread to find out what people are actually talking about here.

[PaperNotes]

Originally Posted by analogika 

It is NOT STATIC and you are WRONG about the "wear-in" period, unless you are talking about many years, which I cannot verify.

I have had seven PowerBooks. All had harder shocks at the start than after a few months of regular use in particular the aluminum version. I'm not feeling any shocks on my current two year old version and have not felt a tingle for a very very long time.

[seanc]

Originally Posted by PaperNotes 

I have had seven PowerBooks. All had harder shocks at the start than after a few months of regular use in particular the aluminum version. I'm not feeling any shocks on my current two year old version and have not felt a tingle for a very very long time.

You're probably just used to it.

[Simon]

Or with time there's a lot of crap and gunk on the case that's acting as an insulator. No seriously, this idea of static on the new case and the buyer having to wear it in is just ridiculous. If there were any static charge on the case when it comes form the factory you could ground the case once (which you BTW are doing when you feel the 'tingle') and it would be gone. There is no such thing as 'wearing it in' to get rid of static.

Again: Use the grounded (three prong) adapter. If you then still feel anything your socket and/or ground wiring are faulty.

[analogika]

Originally Posted by PaperNotes 

I have had seven PowerBooks. All had harder shocks at the start than after a few months of regular use in particular the aluminum version. I'm not feeling any shocks on my current two year old version and have not felt a tingle for a very very long time.

Not to wave my e-penis about (though I'm sorry about your personal lack of "tingle" ):

I have had two, actually work in an Apple authorized reseller/repair center, and was told this EXPLICITLY BY APPLE SUPPORT on the telephone (they then offered to send me additional grounded cables when I explained that I was concerned about fairly valuable audio production equipment producing sparks when connected, and not being pleased about having to carry around the extension cable as well).

[PaperNotes]

Originally Posted by analogika 

I have had two, actually work in an Apple authorized reseller/repair center, and was told this EXPLICITLY BY APPLE SUPPORT

Yeah you waved your iPenis about.

[analogika]

That bit was about the "tingle". Couldn't let that one pass.

Sorry to see you missed it. It compounds the misery of being wrong.

[ghporter]

PaperNotes, it is physically impossible for a CONSTANT static charge to exist and at the same time give you a shock/tingle/noticeable anything. Either the charge is there and it is conducted to you and thus used up, or it's something else that is doing this. Decades of experience with electronic maintenance (I'm waving my fancy tweaking screwdriver about now) tell me that you have a grounding problem. A minor one probably, but grounding nonetheless.

Now if you want to compare certifications, training, degrees, etc. on this subject, I'll start with an associates degree in "Electronic Systems Technology" from CCAF that may be older than you are, a BS (honors) in Computer Science from USM, a Master Instructor certificate and an Occupational Instructor Certificate from CCAF. My second associates is in "Instructional Systems Technologies" and I have very successfully taught people who could not properly replace a lightbulb how complex systems work. Wanna discuss the innards of a switching power supply? Not the ones that run on two chips and a regulator, one that's built from transistors, diodes, capacitors and SCRs.

In other words, nobody here is blowing smoke about this being a grounding issue. If you search this forum, you'll see that this has come up a number of times. Apple's technical documents for EVERY metal-cased laptop have included a note that a minor leakage current may potentially be felt when certain circumstances are met, including using a two-prong power adapter instead of the three-prong, grounded cord.

[analogika]

ghporter wins!

[Edit: epenis image snipped, because the domain has since replaced it with a MASSIVE REAL PENIS to discourage hotlinking. Um. Sorry. ]