Electrified Cases on Macbook Pro!! More common problem?

Oben

This is why I don't understand how Apple can ship the Brick with a two prong, ungrounded, plug. I always use the corded plug so that I have a ground. If you do that, the "texture" "fuzz" "fuzz" etc., is gone.

Bob

Which power supply cord does Apple provide with the MBP:

NEMA 5-15: http://www.interpower.com/ic/images/P18photo.jpg

or

NEMA 1-15: http://www.interpower.com/ic/images/NAPlugphoto.jpg

In addition, on the underside of the MBP, would someone take a picture of the agency certification marks and post a link to view them. I believe Apple is using CSA for their North American certifications.

The CSA NRTL/C Mark is in the second row on this page: http://www.csa-international.org/certificationmarks/marks_forus/

Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

Actually, I'm not sure what you are getting at here. The deal is this:

1) use the two prong plug on the brick, plugged directly into an outlet, you get the "fuzz".

2) use the three prong (grounded) plug on the brick, you do NOT get the "fuzz".

This is obviously a grounding problem and one that is on my PowerBook also. I also happen to know from my business, that PowerBooks and MBP's are not allowed in magnetically sensitive areas of IT centers without the grounded plug. I think this is a worse design flaw than anything else on this forum - but people do not like using the three prong cord. Silly...

I bought two spare power supplies with my MBP. As I did with the first supply, I took the two prong plugs and tossed them away. Too dangerous, IMHO, and that of my engineers.

Bob

Bob,

Either the power supply for the MBP is Class I equipment (earthed) or Class II (not earthed). It can't be both.

If the power supply has this type of appliance inlet: http://www.interpower.com/ic/images/8301311spec.jpg

that indicates it is Class I equipment and must be used with a grounded power supply cord.

When you say individuals are using a two prong plug do you mean they are using a so-called cheater plug without an earth pin. If that is the case and these individuals are getting shocked when they touch accessible metal, then there is the possibility that the insulation has been compromised and the product is not safe to use.

Howard

Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

Howard,

I take it then that you don't have an MBP? Otherwise you would know.

The brick has a "slide off" cord/connector. You can slide off the two prong and put on the three prong. Now, there is a metal snap that hold the connectors in, and whethor or not this provides any grounding I don't know.

Categorically, however, because I have to know this as I work in hospitals extensively, the MBP as well as my PowerBook exhibit the same behaviour. No doubt about it. Oh and this has been covered here before, and with the same discussion / results.

Bob

I never experienced this because at home I plug the brick into a APC power surge strip and maybe that gives me the ground since it's power cord is 3 prong. Bob is right. I work in hospitals too and they are very strict on what gets plugged in, especially in critical areas.

Bob,

No, I don't have a MBP, but I am considering one. The threads discussing individuals getting shocked caught my attention because I am product safety engineer. I investigate ITE products to international standards for regulatory compliance.

I checked Apple's site to see if I could download a manual for the MBP, but only the PowerBook and Mac mini were available.

From the picture and technical specifications on Apple's site the power supply appears to be a direct plug-in type instead of a cord connected brick. From what you have stated previously it now sounds like Apple is supplying different removable faceplates with different blade configurations. If Apple is supplying both the NEMA 1-15 and 5-15 configurations this would be in violation of their UL/CSA 60950-1 Certification. The picture from Apple's site shows a NEMA 1-15 configuration installed on the MacBook Pro power adapter.

Howard

Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

Howard,

I bought my first Mac last July. It was / is a PowerBook G4 1.5GHz 12" notebook. I was one of the first to order the MacBook Pro within an hour of the Keynote address last January. As far as I know, all PowerBooks, and definately all MBP's (and most likely iBooks as well) use the same type of brick power block with the computers. They ship you a "brick" and the "default" connector on it is the two prong, direct to jack type. You, optionally, can remove that plug, and connect the three prong (grounded) cord, which is what I do. This three pronged approach stops the "fuzzy" feeling that is associated with the device not being grounded. My chief engineer in my company was shocked (pardon the pun) to see that this was the case! I've been running it with the three prong cord literally since the day I bought it, and don't have any intentions of switching.

I am not familiar with the NEMA standards for plugs and grounding. (I have my hands full with thier DICOM standard, believe me!). I do know that Oregon is one state where if I showed up with a computer that wasn't grounded correctly, and if the Bio-Engineer is up to the job, he would toss me right out the door! Canada - same thing! I go to Vancouver and Toronto alot and run into the same thing. In any case, I cannot for the life of me understand how this gets UL approval in the States, but, on the other hand, the brick probably does, and not the notebook (when connected to DC all bets are off on regulatory affairs!).

Here is a direct link to the MacBook Pro support site where you will find a link to the manual:
http://www.apple.com/support/macbookpro/

Bob

Ya i posted about this with the same issue. However, my shocks from the case were really painfull. I had red lines all over my forearms where my MBP has shocked me. Apple sent me a new one.

Nothing new. All G4 PowerBooks have metal cases also, beginning with the TiBook. There are also other vendors using metal cases. In all of them, especially if a two-prong connector to AC is used for the power supply, there is the possibility of a slight 'tingly' feeling. I'm not aware of any history of injury or fire hazard or whatever, unless the computer is damaged. (Yes, power supplies have failed and constituted a fire hazard, but that's another issue.)

In conditions of low humidity, especially when one is walking on carpets, a static electricity charge can build up. The resulting discharge can result in a visible arc and quite a shock. If you want to play with that, scuff your shoes on a carpet and touch a metal radiator. But it's not a good idea to do that to your computer. Again, don't confuse static discharges with current leakage by the computer.

Apple meets the UL specifications in the U.S. and elsewhere. But I think the three-prong hookup supplied by Apple is a good idea.

In any case, please don't try to use your MacBook Pro (or any other electrical appliance) while you are taking a bath. 🙂

Here is the link to MBPs product manual http://manuals.info.apple.com/en/MacBookPro_UsersGuide.pdf.

I've had every model of PowerBook G4 and I don't really see any difference in the MBP compared to them. On AC with the two pin plug you can get some electric feel sometimes. As others have said using the three prong will fix it. I also find it very intermittent, it's not a constant thing.

It's no better or worse than the Titanium or Aluminum PowerBooks.

The "pins and needles" sensation you feel as you rub your finger across brushed aluminum is not an electrical shock. It is a physiological phenomenon that occurs when the different sensory receptors in your fingers receive signals of a certain frequency generated by the moving the finger across the ridges of the aluminum surface. It feels a lot like an electrical shock, but it's not.

You'll notice that if you move your fingers too slow or to fast the sensation will disappear or diminish greatly. The sensation will also change depending on how softly or hard you press your fingers to the surface. Once the deep pressure sensors get involved, the brain interprets the signals differently.

I'm not making this up. Its a well-known physiological phenomenon.

If there were actually a potential on the case, you would not need to move your fingers to feel it. Furthermore, the presence or absence of a potential can be easily determined with a simple volt meter.

Here's another aspect to consider. The output of wall-wart power supply is isolated from the household AC. The output is probably around 12 volts and the current limited to produce no more than 65 watts. You can put your fingers directly on the terminals of the power adaptor output and not get shocked. You wouldn't want to put your tongue on it, but, hey, there's got to be some line where the responsibility belongs to the individual.

So, before anyone starts claiming that there is a power safety issue with the MBP, please get a multimeter out and confirm it. Tingles as you rub aluminum proves nothing. Well, actually it does prove something that is known...your sensory receptors can produce odd feelings when stimulated in certain ways.


Power Mac G4 (AGP) 500MHz Mac OS X (10.4.5)

"The "pins and needles" sensation you feel as you rub your finger across brushed aluminum is not an electrical shock. It is a physiological phenomenon that occurs when the different sensory receptors in your fingers receive signals of a certain frequency generated by the moving the finger across the ridges of the aluminum surface. It feels a lot like an electrical shock, but it's not."

Absurd, Peter. The sensation is an electrical shock. The PowerBook adapter places one-half of the line voltage onto the chassis and, therefore, the case. The power is very low, well within international safety standards.