Question ASRock B550 Phantom Gaming 4/ac - new build won't boot

[VinceLe]

I have built a new pc, and it won't boot. No video at all. The CPU and DRAM red LED lights are lighting up on the mobo on power-on

CPU - AMD Ryzen 5 3600XT
MOBO - ASRock B550 Phantom Gaming 4 AC
RAM - Crucial Ballistix 3200 MHz DDR4 DRAM (16GBx2)
STORAGE - Western Digital 1TB WD Blue SN550 NVMe SSD
VIDEO - XFX RX 5600 XT THICC II PRO

No OS is installed yet. I can't even get to the BIOS screen - I get no video at all.

I don't have any other desktop computers, so I can't swap components to test what is working and what is not working.

Any help would be greatly appreciated.

 

[rgd1101]

make and model of the psu?

 

[VinceLe]

PSU - Corsair RM550x

Thanks for your reply.