Looking for some tech support please.

I've just put my PC together and I can't find the problem. I have no video output at all. (Yes I'm plugged into the GPU).

My part list is as follows:

PCPartPicker Part List: https://uk.pcpartpicker.com/list/2VpWK3

CPU: AMD Ryzen 5 5600X 3.7 GHz 6-Core Processor (£309.98 @ Scan.co.uk)

Motherboard: Gigabyte B550 GAMING X ATX AM4 Motherboard (£143.63 @ Overclockers.co.uk)

Memory: Corsair Vengeance LPX 32 GB (2 x 16 GB) DDR4-3200 CL16 Memory (£118.71 @ Ebuyer)

Storage: Samsung 970 Evo Plus 500 GB M.2-2280 NVME Solid State Drive (£88.99 @ CCL Computers)

Storage: Seagate Barracuda Compute 2 TB 3.5" 7200RPM Internal Hard Drive (£50.74 @ CCL Computers)

Video Card: Gigabyte GeForce RTX 3070 8 GB GAMING OC Video Card (£619.98 @ Ebuyer)

Case: Corsair 275R Airflow ATX Mid Tower Case (£88.40 @ Alza)

Power Supply: Corsair RM (2019) 750 W 80 Gold Certified Fully Modular ATX Power Supply (£124.97 @ Laptops Direct)

I'm getting power as my GPU is showing RGB and my fans are all spinning.

I've flashed the BIOS with the most recent release from the manufacturer.

Still, no video output via Hdmi or Display Port.

The only thing I can note is the Stock CPU fan is intermittently speeding up and then stopping in a loop.

Any ideas?

Regards

One very sad first time builder