I'm sorry to hear for your HD7990.
The worse thing is when no more warranty and hardware still work and than something like this happen and GPU die.
Bad luck.

enrique145
I guess one has to become a computer and electrical engineer to not be afraid to use a GPU and a PSU. I read 750W PSU on the box of the GPU and assumed the 850w PSU would suffice, but wrong I was. The 7990 is out of warranty, so to the garbage/recycling bin it goes. I would post pics, but there was no physical damage to it. I stopped the burning madness on time, before the 8 pin connected to the GPU melted too.  All I know is, the GPU does not work anymore since this event. Well, as soon as that replacement arrives, on sale it goes, and so the other parts of the computer. I will buy a  prebuilt computer, probably a Mac and forget about building my own computer again. It is definitely not for me.  Thanks a lot for your opinions, I really appreciate them. Good Luck! 

I wouldn't blame yourself for faulty hardware acting up. The circuit board on our brand new Trane XV95 central Heat/Air furnace fried itself two different times within the first year.  
 
 
 
 
 

I just had similar event and noticed that my VGA port and cable melted at the PSU. Its a P2 1000w PSU about 3 months old. So I'm digging through info now about RMA. So it looks like I will have to pay for postage, right? Anything else I should be aware of? I wonder if I should just get a new cable and clean out the melted port? Also, does anyone know why they use only 18 AWG cable for their pcie connectors?
 
note PSU appears to be functioning, but one of the VGA ports is a little melt warped. Haven't done too many tests to confirm extent of damage.
 
ok thanks for help below... 

Great First Post p2andrew for 2017.
Did you read Post #7 above?
"Long story short = A PSU will supply only what it's asked to supply, up to a point, by the hardware, even faulty hardware..Almost certainly not the fault of the PSU."
Maybe you should have created your own Thread as you do have a different PSU an unknown Graphics Cards an unknown Motherboard.
The EVGA GQ 850 Gold PSU and the P2 1000w PSU are not the Same Power Supplies.
Any Photos to show the damage you are writing about?

Hello p2andrew,
 
We are sorry to hear about your issue. I will follow up with you personally. 

Bob's answer was great but I just want to add one thing. As Bob said that is a single rail psu and I find it odd that an EVGA moderator would suggest using 2 separate cables since that wouldn't make any difference. The only way that would matter is if the resistance of the psu cable was high enough, which its not, you could safely send like 30 amps through those cords. Like Bob said though, the fault was the GPU and it caused the psu to send too much power which caused a surge back down the line melting the connectors. EVGA's awesome customer service is still replacing your psu despite it not really being their products fault. If you want more help post detailed pictures of the graphics card after you remove the fan and casing. You most likely blew a capacitor and that's can be a cheap easy fix. Just need a capacitor which you can get from AMD and $10 soldering iron. GPU chip could also be fried then it would be done. Also its a good reason to always by EVGA they would have most likely replaced the Graphics card too had it been one of theirs even if outside the 3 yr warranty.
Also friends don't let friends buy Apple Computers don't do it!!   

I have similar situation as you, but distributor on my country (Indonesia) refuse to replace my PSU
short story is, i buy a brand new two EVGA power supply 750G3 and 550GQ in June 2017, and then the 550GQ burned when i attach it into my motherboard and one cable is melted, i'm really sure that i receive defected product, so I return it to EVGA distributor in my country, but they refuse to replace my PSU, and tell me to post in this forum for warranty, what the??