First time PC build but no posting or beep sounds

[SidJJ]

I have followed the user manual and online tutorials to setup the system for the first boot. When I switch on, the CPU fan is running, the light comes from the SSD (red LED light), the GPU fan runs (I have connected my monitor to the GPU via HDMI cable) and even the RGB light is on in the motherboard. But I'm not getting any display on my monitor. No-fault with the monitor, it is working perfectly fine with other motherboards.

My setup is -
Ryzen 5 3500
Asrock Steel Legend 450M Motherboard
2x8GB DDR4 3000 Mhz
Nvidia RTX 2060 Super
550W PSU
500GB SSD M.2

Please help. I'm attaching a pic. What am I doing wrong?!

 

[Cycloid Torus]

I hope I have this right: no POST, no error messages, power (as evidenced by fans) is getting to the motherboard.

Some helpful ideas, see: https://www.computerhope.com/issues/ch000607.htm

In the past some of my screw-ups have been improperly connected case front connections, missed full connection on 6-pin / 8-pin additional power connectors (I think you have 2 in addition to the 'big one' - and I do not see them) and incompletely inserted RAM stick - and one case of an improperly inserted CPU (cockeyed - and I still do not understand how I did that). In your case I would double check manual as to where RAM should go - it is possible you are only allowed to populate certain rows.

ALSO: possible one of the standoffs under the mainboard could be in wrong place...happens.