Macbook Pro static electricity, is this normal?

sweejin said:

i posted this in the Apple support forums, so i thought if anyone stumbled across looking for a solution, they may find it here as well

i just purchased my MacBook Air 13" 256 GB SSD 2011 today in Kuala Lumpur, Malaysia, and i too noticed this so called "vibration/electrostatic sensation" problem when the mains is plugged into the wall socket.

initially, i thought it was a normal feature of Mac's, as this would be my first MacBook i'm owning. however, i thought about my friends MacBooks and they don't have this problem, and all the display demos in the Apple outlets. the feeling is described as vibrations or ever slight eletrostatic discharges when i place either or both hands on the metallic unibody. and i wasn't comfortable with such a feedback. what was worse was, i thought about leaving it charge for awhile without touching it, and when i handled my MBA, i got a severe shock!

i Googled and found many people have this issue. and it has persisted in different countries around the world since 2007. i found it appaling that such an expensive piece of hardware could have a potentially health hazard and/or poor quality control.

many websites/posters blamed it on the a faulty MB or 45W MagSafe Power Adapter, or poor grounding of the outlet/building power supply, which i thought was ridiculous as i've not had any electrical problems with all my other electrical appliances.

i followed different advice, including getting a voltage regulator, moving to different power sockets, or even charging from different building/sites, however, the problem still was there. i even used the grounded 3-pronged head provided instead of the default 2-prong head (in Malaysia, we use the same 3-hole socket types like in the UK/Ireland), but felt that there was a current leakage into my MBA unibody.

SOLVED: until, i found a post by someone who suggested using the AC extension power cord also provided in addition to the MagSage Power Adapter. and it worked! no more vibration or "electrostatic discharge" on the unibody.

and then i wondered, why in the world should there be a difference. i thought perhaps, the MagSage Power Adapter was faulted. and then i looked closer at the Wattage and Current ratings.... what a shock!

OBSERVATIONS: i found there were slight different fuse ratings used in all 4 components MagSafe Power Adapter, default 2-prong adapter head, 3-prong adapter head and the AC extension power cord.

MagSafe Power Adapter body: Output 14.5V 3.1A (Voltage/Current supplied to MBA)
2-prong adapter head: Input 125V~ 2.5A (Voltage used in countries like the USA)
3-prong adapter head: Input 100-240V 2.5A (for countries that use 220V like the UK, and for additional grounding for all countries)
AC extension power cord: Input 100-250V 3A (notice the higher fuse rating)

i may be wrong, but the 0.5-06A difference of current from the input to output, may be allowed to leaked into the MBA, and cause vibrations/electrostatic discharges when touched, and i think may damage the components down the road.

the only to see if my theory is correct is to go to the hardware store and obtain a 3.0A fuse and replace that in the 3-prong adapter head and see if it resolves the problem. i will let you guys know.

but in the meantime for people who have that problem, i recommend using the AC extension power cord as well.

good luck!

Click to expand...

Lycragon said:

I'm from Malaysia too and recent got my first Macbook, after going through all those "use 3-pronged plug, make sure your house is really grounded" stuffs, yours is the only one that actually works! Thanks a bunch!

If you're still reading this forum, would love to hear if the fuse switching solution works.

Once again, thanks!

Click to expand...