Think I have broken my HD7950...

[Seriously]

2) With one power plug out (or both, or GPU out completely) of the GPU, the onboard ONLY works. PC starts up and everything else works fine.

Is this correct (You are confusing the issue, take it slow)

Without the GPU card everything works?
With the GPU card everything fails.

If that is the case check the power supply and/or the GPU.

 

[Seriously]

Were you standing on a carpet when you were working on your PC?

Rickster PLEASE!

 

[quax]

Is this correct (You are confusing the issue, take it slow)

Without the GPU card everything works?
With the GPU card everything fails.

If that is the case check the power supply and/or the GPU.

This is correct.

When the GPU is in and everything fails, there is power because all the fans spin.

 

[Seriously]

This is correct.

When the GPU is in and everything fails, there is power because all the fans spin.

Test that GPU with another PC set-up or bigger power supply. Seems it's a goner.

 

[quax]

Test that GPU with another PC set-up or bigger power supply. Seems it's a goner.

Ffffffuuuuu! I hope not the case. But either way something has gone. Everything is under a year old...

 

[quax]

Will check the GPU out the weekend.