Raja, I cannot seem to video a tutorial on getting the GPU out, do you remember where you saw this?
https://www.youtube.com/watch?v=Ysk8d_kRg0o
This is how to remove a card out of a motherboard.... Joke?
I was talking about removing a GPU (the chip) out of the HD7990 PCB (the card)!
And all this time I've been thinking that how stupid you are... Funny. I didn't have any experience with that particular card, and didn't know that it comes as twin, in fact, I've no experience with any sort of joint/twin GPU's.
Seems like there isn't much hope for your card left, honestly. Check out if there is any bios reset switch or something around the GPU, otherwise it's pretty much gone.