Snap Crackle...

Ooooh, I just had a worrysome thing happen with my Sony GRX570.

I was plugged into wall power and decided to move outside to the deck to work 
outside in the nice weather.

Found an extension cord, plugged it in, pulled the sony powersupply cord out 
of the wall and plugged it into the extension.

There was a visable and noisy snap - sounded like a short. Quickly unplugged, 
checked the laptop, and it seemed ok.

Looked at the plug and noticed that the sony plug (USA model) is a simple two 
prong plug with no polarity sizeing on the prongs.

The extension did have polarity sockets and the wall plug obviously did too.

I could tell by the way I was holding them (remember this all happened in a 
second) that the sony plug had been in the wall in the reverse position of 
how I had plugged it into the extension cord.

I think what I heard was the transformer in the brick dischargeing through the 
now reversed polarity plug-in. (Transformers can deliver quite a punch 
immedialtly after they are unplugged as their magnetic field decays.

I reversed the plug, back to original polarity and plugged it in again and all 
is fine.

Moral: Since sony's plugs are non-polarity keyed, its best to give the brick a 
second of three when changeing power sources.

-- John Andersen - NORCOM http://www.norcomsoftware.com/