Sparks fly from fire wire port

Well, a user accidentally shorting out the power feed in the FW port wouldn't be covered by warranty anyway, cool guy, so the fact that it has expired isn't really relevant. You might want to check whether your household insurance policy covers accidental damage of this kind.

First step in such a situation is to try an SMC reset.

I have had this happen to me twice in the past two weeks on two different 13" MacBook Pros, mine and my fathers. While plugging in another device I brushed up against the FW port once with the mini DVI cable for the adjacent socket, and once with a USB cable on my Father's MBP. In both cases there was a spark and the computer shorted out entirely and had to be reboot.

Both machines are less than a year old. If Apple doesn't think putting external ungrounded, and unprotected, power where it can be brushed against isn't worth warranty protection that is just ridiculous.

Are both units connected to the same properly grounded AC source? This problem is generally indicative of a poor earth-neutral connection and can potentially be lethal. You should have this checked out by a qualified electrician ASAP.

No this happened 400 miles apart with 2 completely different peripheral setups. I was down visiting my father (who is in his 80s) and helping him attach a peripheral device to his 13" MBP. In the case of his the usb cable wasn't even connected to a second device yet.

In the case of mine it was the apple made mini dv to HDMI converter's male plug that had the arcing from the firewire port when brushed up against. This sounds like a very serious design flaw if something touching the surface of the port can cause arcing.

This is not a joke. This happened to me 2 weeks ago. I was plugging my macbook pro mini dvi to hdmi cable into my HT receiver, was adjusting the settings to get multichannel output sound. Things weren't working right so i changed the audio to digital out on the macbook pro. I plugged a mini coax into my Toslink connector on my receiver and missed it by a lil bit, contacting the metal chassis with the plug.

There was a loud and bright visual spark that fried my audio/ video surround sound receiver.

I have done this procedure dozens of times with the power still on in my first gen macbook pro. First time I try it with my new 2010 13in, and my receiver gets fried.