New build works, then explodes, then still works, please help

[roymustang]

I built a new rig yesterday with the following parts:
Cooler Master HAF X case (already had)
OCZ Fatal1ty 750W Power Supply (already had)
Intel i7 2600K
Cooler Master Hyper 212+ (w/ Arctic Silver 5)
Asus P8P67 Deluxe (B3)
8GB G.Skill Sniper DDR3-1600
2x Sapphire 5850 Xtreme (CrossFireX)
Creative Audigy 2 ZS (already had)

The rig booted it up fine, the temps were good, every thing was working great I installed Windows 7 64 bit and drivers last night, then this evening i decide to continue installing software like Winamp, Firefox, AVG, Media Player Classic with video codecs, etc.. I ran Windows Experience that worked fine. Then I decided to to try playing a mkv 720p video and i noticed it was slightly choppy only very slightly though, most people probably wouldn't even notice it. I went in the menu of MPC to see if hardware acceleration was enable and then all of a sudden there's a huge POP and a very noxious burning odor begins to fill the room, I immediately flipped the switch on the power supply.

Then I smelled the power supply and it didn't smell burnt so I opened up the rig and tried to smell the various components and again i could not detect the source of the smell. So then out of desperation i decided to close her back up replug her and boot her up again and she booted right up, no issues and when I got the the screen that said windows shutdown improperly, i decided to turn her off for safety and see if anybody here could help me figure out what the deal is before proceeding further.

My guess is that it was either the 2nd graphics card or the sound card, if it was anything else, with that kind of sound and smell I don't see how the computer could boot up with picture. The sound card is in between the two graphic cards, the only PCI slot I could use and its very tight fit almost touching the graphic cards but i mean these slots are designed so that components don't touch eachother right so I doubt it could have caused a short circuit or something. I should also note that the cards didn't come with a CrossFireX bridge and that I got one off eBay for 5 bucks, but it looked normal enough, don't know if that could be an issue.

Anybody have any ideas as to what this could be?

 

[Motopsychojdn]

if the soundcard is between the two graphics cards, how in hades have you managed to connect the X-fire bridges?
they only reach a card sat in the adjacent slot, not one 3'' away
my guess is that you've damaged at least one of the cards, maybe seriously
**Edit, you say you only had one bridge on there?**
Moto

 

[roymustang]

You only need one CrossFireX bridge to connect 2 cards. It's very common misconception that you need 2, most high end cards have 2 bridge connections so you can do 3-way or 4-way CrossFireX, but you only need one bridge for 2-way, and in fact the 5850 Xtremes I have do not support 3-way or 4-way so there is only 1 bridge connector on them. As for the bridge itself it is standard length to fit in a mobo's first two PCI-E slots (which almost always have 2 slots between them) and my sound card does not stick out more than my two graphic cards so the bridge goes flat over it.

I'm gonna take my sound card and bottom graphic card out in a bit and see if there's damage and test the system without them now, I didn't wanna mess with it last night, it was late and dark.

 

[Motopsychojdn]

Sorry if I was unclear, I was just checking you only used one bridge, not advocating the use of two

I'm off to work myself now so I'll check back and see how you got on in the morning, good plan not working on the rig whilst tired though
Moto