Question No display to monitor, tested with two GPUs ?

[Biggun101]

On my original post , I had tested my 4090 on my new PC build. No display to monitor, LED lights turned on.

I have just tested a 4070TI and same problem, LED come on but no display despite have trying both DP and HDMI.

I checked device manager and everything seems to be working. Could this be a deeper motherboard problem or is this a fault on my end?

I checked both PCI slots for both cards and same problem for each.