"Burned" index fingers from using MacBook Pro trackpad: My index fingers, both hands. which rest on the computer next to the trackpad and/or are used on the trackboard are painful, feel like they have been burned and, I can barely move them. I did

If you feel this is an obvious Hardware issue, and would like to escalate this within Apple, you should present yourself and your equipment at an Appointment at the genius bar at an Apple store, if that is available to you. Otherwise, call Applecare. They will evaluate your computer and discuss its proper operation with you. They will reiterate that Apple equipment meets all applicable safety standards, as implemented by both type testing (for issues like EMI-RFI radiation) and by individual testing (for issues like electrical isolation and proper operation) at the factory. They can retest for proper operation at the Genius Bar, at your request.

Apple will tell you they are unqualified to make any medical diagnosis of what your medical problems, if any, may be, and that you should see your medical doctor. If your doctor can produce some sort of probable causation, they can repair or replace parts in an attempt to remediate whatever the issue appears to be. If a reasonable solution is not found, they will escalate the problem (provided you have provided credible causation mechanism) within engineering for further diagnosis.

I think Ronda Wilson may be onto something.

This graphic comes up when searching for carpal tunnel. I think may be from mayo clinic web site:

as this condition is caused by pinching of nerves in the wrist area, the symptoms you experience can vary widely.

my original statement:

But the DC cord to the computer has only Voltage and return, it does not carry earth ground through to the computer.

with your statement:

Then what is this

Pin 5 is also ground

My point was to clarify what these signals, including those labeled "Ground" actually represent. I was attempting to respond to your challenge.

I suggest that you consult a physician. You may have an allergy or some other rare condition that creates such symptoms. This is the first time I have heard of any one having 'burned' fingers from using a trackpad.

Ciao.

NMRK wrote:

My physicians do not make laptops nor do they understand a "power transmission" through a laptop shell. Tubes in radio's were hot. That was 100 years ago. Something is transmitting power. My fingers aren't "burned" they just feel burned and are now stiff and arthritic. Only the index fingers are impacted even though I use other fingers on the keyboard so it is not the keyboard. Check the internet--I am not the lone ranger re this phenomenon.

Computer techs do not understand skin and nerve damage. Stiff and arthritic fingers fall within the domain of the physician. If your computer is burning your fingers stop using it and take it to an authorized service center for evaluation.

NMRK wrote:

My physicians do not make laptops nor do they understand a "power transmission" through a laptop shell. Tubes in radio's were hot. That was 100 years ago. Something is transmitting power. My fingers aren't "burned" they just feel burned and are now stiff and arthritic. Only the index fingers are impacted even though I use other fingers on the keyboard so it is not the keyboard. Check the internet--I am not the lone ranger re this phenomenon.

Nothing is being "transmitted" through your trackpad. Therefore, your physician doesn't need to know about power transmission. They need to know about what sort of diseases or conditions cause the symptoms you have and what specialists to refer you to, if required.

Good luck on your search for an ambulance chaser looking for "green mail" from deep pockets.

The assertion is, without doubt, the dumbest attempt to squeeze $$$ from a corporation that I have ever seen.

Barry

NMRK wrote:

I did not say it was transmitted through the trackpad--I referred to the adjacent areas--not solely the trackpad. I pasted in a reply from a gentleman that acknowledged that electricity in the laptop COULD leak. I know it is coming from the guts of the machine. I do not need a doctor. I need a lawyer.

The amount of electricity that could "leak" through your computer is not enough to do any damage. Even if it were, it wouldn't' cause the symptoms you're describing. Lawyers aren't very good at medicine (except the ones who are also doctors but they usually specialize in medical malpractice). Even if you did hire a lawyer, the first thing they would do would be to send you off to a doctor to find out what the problem really is.

Trackpads on recent MacBooks are made of glass. The likelihood of transmitting something through that is quite small indeed.

The voltage produced by a properly-operating power adapter is about 16Volts, Direct Current. The battery is also capable of about that range of Voltage. If through some fault, this Voltage were applied to the aluminum shell by accident, the result for most people using such a computer would be -- nothing.

If you use the two-meter AC power cord with your power adapter (rather than the small plug adapter some call a "duck head") you would have the additional benefit of grounding the electronics in the power adapter body. But the DC cord to the computer has only Voltage and return, it does not carry earth ground through to the computer.

Right from the outset, I will tell you that this will not help you.

I have been using Apple notebook computers since 2002 and have been on this site since February of 2003, and I have not ever heard of this problem. It sounds more like carpal tunnel syndrome than anything I've heard of.

As someone who works with sound wiring, you must know that signals labelled "ground" are often named very loosely, and should properly be labeled "signal (or power) return", or "reference", and do not correspond with Earth-Ground.

The signals so labeled in that MagSafe interface are the "return" or "reference" for the second wire, which is "voltage". There are only two wires in the DC cable -- the insulated center conductor, and the 100 percent coverage stranded shielding around it which is pinched into a wire at each end. The Voltage and Return are duplicated so that the MagSafe plug can be installed upright or inverted and will work the same.

Another interesting tidbit is that the center conductor is used for signaling between the computer and the chip in the MagSafe-end. The MagSafe chip sends it type and serial number, and the computer sends a signal that tells the chip when to activate the LED and what color.

Yes, that is exactly what I said. These signals are certainly power return, but it is highly questionable whether they have any correspondence with earth ground.

If you use the "duck head" rather than the two meter power cord, there is no possibility of connection to Earth ground. the dusk head does not carry earth ground from the outlet through to the power adapter body.

Until you have securely connected the Mac for a full second and the computer has signaled to the magsafe chip to go ahead and connect power, adapter power is not applied to the pins at the computer-end. So this will not be easy to measure in the way you have suggested.

As I have a sound background 2 pin connectors are banned (even for signal, let alone power), I always use a ground, and if you don't want to take the time to do the measurement suggested, keep on guessing.

I have done the measurement for another who doubted.