MacBook Pro Al case electrical tingling using 2-prong adaptor on charger

Question

MacBook Pro Aluminum case electrical tingling when using 2-prong adaptor on charger
This applies to the new (late 2008) MacBook Pro with the aluminum unibody enclosure
I've seen several people report this problem, but also I've seen threads about this problem wrongly conflated with other problems. The other threads include:
http://forums.macrumors.com/showthread.php?t=440564
http://discussions.apple.com/thread.jspa?threadID=1757399
http://discussions.apple.com/thread.jspa?threadID=1798538
This thread is specifically about the problem typified as follows:
- This is an electrical tingling. It is not a painful shock or zap. It is most noticeable when brushing against the aluminum surface of the Mac.
- This only occurs when plugged in using the 2-prong adaptor, not when using the 3 prong, not when running on battery (not plugged in).
- It does not always occur. It seems to happen when plugged in with the 2-prong adaptor for an extended period like overnight.
- This is not a physical vibration, and has no audible component.
- I have verified that the outlet is wired properly: correct polarity, effective grounding, correct voltage, neutral does not appear to be floating
Here is my story of trying to get this fixed so far:
1. Call #1 to Apple Support
- They told me they had never heard of this problem before
- They said I should reset the SMC (http://support.apple.com/kb/HT1411). This strikes me as a simple if-all-else-fails-reboot solution. Not sure how a firmware reset will affect a hardware problem
- They then said they have seen this problem before and it is caused by faulty wiring. (yes, contradicts the first statement). This too seems like a cop out. I'll have to check it out though.
2. Call #2 to Apple Support
- "It says here you are hearing some sort of vibration" (aaaaaarg....no!)
- We recommend using the 3 prong adaptor
- You should bring in the machine to an Apple store to be fixed. Yes this is a known problem and we have a solution. I made an appointment to bring it in.
- I asked for a reference for this known problem and was told "CP 191"
3. Trip to see the "genius" at the Apple Store
- The genius starts out by telling me, " Sure, I've heard of other Macs doing this. I once had an old MacBook that did this."
- He then goes in the back with the machine to "test it"
- He comes out and says he was unable to duplicate the problem. This is not a surprise since it takes hours for it to manifest.
- He then proceeds to tell me that when it is ungrounded (such as using the 3 prong), then this is expected.
I am stunned. Thereafter ensues a long conversation of him trying to convince me that it is not a defect that this laptop, when used with factory supplied 2-prong adaptor, exhibits an electrical charge shocking the user. Some of his arguments:
- it's a complicated piece of power using machinery, like a car. To which I replied that if I had a car that shocked me when I tuned the radio, I would demand it be fixed.
- I asked him for Apple documentation that states that this is the expected behavior. All he could produce was documentation recommending that 3 prong adaptor be used when possible.
- He told me that all laptops are grounded through their cases. I said fine, but a properly functioning laptop would not need to shed excess voltage such that the user can feel it.
- It's just static electricity that builds up on this case
- You can place a shield or protector over the aluminum palm rest.
He told me that since we were past the 14 day window, he could not replace the laptop. I asked if it made a difference that the ticket was opened in the first 14 days and he said no. I asked if I could get just a replacement power brick to see if that made a difference. He replied that they did not have those parts available.
After arguing for over an hour, and it being clear that I was not going to just leave, he finally brought the manager over. She asked what I wanted and I reiterated that all I wanted was for the laptop to be repaired or replaced. She agreed to replace it, but...
- Since it was bought online it would need to be sent back (could not be replaced in the store). It would take 7-10 days
- They would not assist in any way in backing up or transferring the data. We would lose everything n the drive (as it was being replaced). I could not keep the old drive and just send the computer back
- The new one might also exhibit the problem. One of geniuses volunteered that he was sure it would. (IMO, if true, this simply means that the model is defectively designed)
story to be continued.....

Answer 1

Unfortunately, I went through the same thing. I do believe my issue was different, though (vibration).
I received contradictory information from 4 or 5 Apple reps over the phone, the Apple retail store refused to repair/replace the machine, and I was told that I may have to pay for labour if I took it to a reseller (obviously incorrect). In the end, I just returned the **** thing and bought a Macbook in-store. With the money I saved, I'm going to build a desktop PC with twice the power.
In my opinion, the service was much worse than the defective machine. I came very close to not buying another mac...