Question PC wont POST (VGA Light)

[BJDubb]

Hi,
My computer has stopped turning on recently, so I pulled it apart and tried to diagnose the problem. I got pretty far and eventually realised I needed a new Mobo.
The old system was:
i7 8700K
16gb 3400mhz Corsair Vengeance Pro
Aorus RTX 2070 Super
Asus ROG Strix Z370-H Mobo
Antec 850W Gold+ PSU

I ordered a new Mobo bundle with a Z590 mobo, i7 10700KF and 32gb of 3400mhz ram. Assembled all the parts to be left with a VGA light on boot. I had read online that it could be a faulty power supply, which i thought was fair enough considering the previous PSU was 3+ years old now. So i got a new RM750 PSU and now I am still getting the same VGA light.
What ive tried:
-Clearing CMOS by taking battery out
-Reseating all parts
-Loosening CPU
-Tried different PCIE slot for GPU.

Ive come to the conclusion that its a setting within the bios preventing my gpu from working but I cant change it because the cpu ive got doesnt have an iGPU.

Any tips/suggestions would be greatly appreciated. Thanks

 

[egda23]

Did you test this GPU in another PC ?
Are you sure that it was functioning all along ?