I think my graphics card is gone and took 2 motherboards with it

[M86ney]

BACKSTORY:
i was on my computer about a week ago and the screen just went dead so after swapping parts with my brothers computer i came to the conclusion that the AGP port on my motherboard was shot, so i sent it back to ebuyer.com and they said it was faulty and sent me a replacement.

TODAY:
my new motherboard came. YAY!
so i pluged it in and STILL the same problem $*!£#@&~

then i thought that the problem must be with my graphics card, so i got the graphics card out of my brothers computer and it STILL didnt work.
i then came to the conclusion that maybe my graphics card is shorting out the AGP port on the motherboard, so i put my graphics card in my brothers computer to be sure(the screen still didnt come on)

at this point im thinking great iv shorted two motherboards to find out that my graphics card doesnt work, so i put my brothers computer back together and sure enough it all switched on(even the monitor). WTF!

SUMMERY:
my graphics card doesnt work in either computer
my brothers graphics card works in his computer but not mine.

Does anyone have any other ideas whats wrong with my computer?
Thank you in advance.

 

[m3trj]

Well your graphics card doesn't work that's for sure, and it looks like it took your second motherboard with it. Send them both back to ebuyer and ask them to test them together maybe.

 

[M86ney]

ok, i just thought that i would add that when i was testing them i was pluging my monitor into my brothers computer so seen as it switched on when it had all his bits in so i know that the monitor works.