Got extremely lucky today..

OK, just to explain what happened:

Customer+iMac 27mid2010 (A) wants a videocard upgrade (had a 2GB card laying around that i sold him for a lower price so i could keep the old (1GB) one.
Job done.
Customer +iMac 27late2009 (B) walks in and wants to buy the leftover 1GB card because her current one has pink stripes onscreen.
I install card A into machine B, and no dice: whatthefuck has the card just died on me?
I take card A out and test it in a knowngood iMac late2009 ( C ) , no dice.

I take card C and install it back in machine C: no dice.
Machine B now won't accept any videocard.

Can someone help me gain a clear head on this, because i thought that all 27" videocards are intercompatible.
Is a defective videocard destroying all my iMacs? (Card B has been happily rendering Vectorworks stuff for the past 7 years, it seems funky for it to die in my careful hands today)

Maybe it's friday, but this shit is killing me.

Much obliged


You cannot just swap a 6970 is a 2010 machine. For one it will have no thermal control as the card is not supported and it will not read the sensors. That 6970 is going to die very soon like they all are doing as it is now cooking itself.

All the cards will give an image at least. How many LEDs are lighting up now? Need to remove the tape from the LEDs to see them on 09/10 machines.
Ah crap, i didn’t know that!! I thought all 27” cards were interchangeable between 2009-2011? Should I tell client A to install some fan control software, cause I think that he will want to keep it for rendering.
I know about the leds, I’ve taken all of the tape off and on all machines only the first two light up. Will doublecheck tomorrow when back in the shop.