[SOLVED] CPU/MOBO doesn't detects any GPU

[qounik]

I had a perfectly running PC. Then a while back I bought a new casing for it. I swapped all components from my old case to new one myself and afterwards when I turned on my PC, there was no output through the Nvidia GPU.
After some minor troubleshooting I disconnected the whole GPU and started the PC up with the internal Intel graphics driver. The monitor now has output and everything else is running fine as of now, except for the GPU.
Retried again for any change in results, no luck. Checked all driver settings, the BIOS display output preferences, still all same. So I tried a different GPU from another PC, and still the external GPU didn't show up. I tried my GPU and POWER SUPPLY on another PC and it worked on that PC.
Basically after some research and consultation, I came to the conclusion that motherboard might be the issue. Then I got a motherboard to prove my theory, but there's no output through these new motherboard as well. This is the current situation.
What could be the underlying cause of the problem? Can it be the processor somehow? Why the problem would arise suddenly? Any help will be appreciated.

CPU: i7 6700
GPU: GTX 1050 Ti OC

 

[helpstar]

which motherboard is it? Did aou replace it with the same model?

Did you clear the CMOS (BIOS reset) before booting with the nvidia card?

Try the motherboard outside the case with a minimum setup
PSU, motherboard, CPU+cooler, GPU, RAM, monitor connected to GPU

did you connect the monitor only to the 1050 and no other display cable was connected to the motherboard? Even if there is no monitor connected.

Is the BIOS up to date?

 

[Mtop]

Make sure card is seated properly, 1 problem here was that card interfered at the back of the computer and couldn't be seated due to being slightly bent. So fully seated and powered - check both ends of the cables.

 

[InvalidError]

Assuming everything was hooked up properly during your tests, the only reason I can think of for the computer to have no display while using discrete graphics after trying different GPUs and motherboards would be that the CPU's x16 PCIe interface has died. The most likely way this might happen during a case swap would be static discharge through a PCIe trace, be it from your finger to the trace (ex.: grabbing the board from a random place instead of the metal shields on IO connectors or other exposed metal electrically connected to the board's ground plane) or from the trace to ground (ex: motherboard tray standoff while bringing the motherboard in), hence the importance of making sure both the case and board are at the same potential before putting them together.