No output image to my screen

[ShowFreak]

Basically I had a AMD a10-7850k APU and it had an integrated graphics card and I have a AMD R9 290 graphics card and it kept going on my integrated one on programs and games. I went into my BIOS and went into peripherals and disabled the internal graphics I THINK and the screen didn't get any output image, it did not detect anything. it was in the old GIGABYTE BIOS menu the old school one. So I brought a new CPU and new mother board:

Intel Core I5-4460 and MSI Z97 gaming 5 motherboard, but the problem did not get fixed, I think it is something with my graphics card but I cant know for sure, how can I fix this?

I also have a video on this: https://www.youtube.com/watch?v=lj4OsYUfJ0w

 

[ranco58]

If the GPU does not work on either motherboard then it is bad and will need to be replaced.

Ranco58

 

[ShowFreak]

If the GPU does not work on either motherboard then it is bad and will need to be replaced.

Ranco58

How can it be that by disabling my internal graphics that it ruined the graphics card?

 

[ranco58]

No that should not have affected it, Does the GPU have connections for power cable from the power supply ? If so then I have seen people use too small of a PS not capable of enough power damage the video cards just like not connecting the PS to video card if required damaging it also.
Ranco58