Question Is PCI-E x16 port damaged?

[raunak62]

With GPU connected, after turning on the PC, no beep sound comes. Probably POST test failure. As a result, no display on monitor (but GPU fan was spinning). Next, I removed the GPU and connected the DVI cable to the motherboard port. After turning on the system, PC boots normally and display works. Thought GPU might be damaged, so tried using it in a friend's PC. There, the GPU works fine. Tried with the same DVI cable too. So the cable is also not the issue and neither the GPU.
Next, I connected my friend's GPU (Sapphire Radeon R7 260X) in my PC. This time, after booting the PC, it got past the POST test and gave the normal beep sound but still no display. GPU fan etc were all spinning. R7 260x requires a 6pin connected but my PSU Corsair VS550 should be able to provide ample power. Also tried a different DVI cable, still no display.
Tried resetting the bios manually from motherboard. Also checked that BIOS is configured properly to use PCIE first.

Summary:
My GPU + My PC -> no display, no beep sound
My GPU + Friend's PC -> display works
Friend's GPU + My PC -> no display, but successful POST beep sound
My PC + on-board mobo graphics (no GPU connected) -> display works, PC boots normally

System SPECS:
CPU: AMD FX 6300
Motherboard: Gigabyte GA78LMT-USB3
RAM: 4GB + 2GB
GPU: MSI Geforce GTX 1050Ti 4GB OC
PSU: Corsair VS550

 

[Lutfij]

How old is that PSU? The VS series is more of an expensive paperweight.

 

[raunak62]

How old is that PSU? The VS series is more of an expensive paperweight.

Recently bought. Hardly 2 weeks old.

 

[AllanGH]

Have you tried the GPU in a different PCIe slot on your MB....what happens in that test case?

 

[raunak62]

Have you tried the GPU in a different PCIe slot on your MB....what happens in that test case?

Mentioned motherboard model. Only 1 PCIE slot.

 

[AllanGH]

And you actually expect ME to look up the motherboard...at 5:30 AM???

What nerve!

OK....so much for that genius idea.

If you've already tried it with a different PSU, and gotten the same results, then it's down to replacing the MB.

 

[raunak62]

And you actually expect ME to look up the motherboard...at 5:30 AM???

What nerve!

OK....so much for that genius idea.

If you've already tried it with a different PSU, and gotten the same results, then it's down to replacing the MB.

Any other tests I can perform to be absolutely sure? The motherboard works fine otherwise.
How am I supposed to know when someone is going to reply! Gave all the relevant info so that the thread won't be cluttered.

 

[AllanGH]

Relax...I was joking.