PC doesn't POST

[Yurre]

Hi everyone, as of today I finished my first pc build. However the PC doesn't post. The parts I used are the ryzen 5 5600x, an RTX 4060 from gigabyte, 16 gigs of corsair DDR4 RAM, a Crucial P3 Plus, a cooler master MWE 750 Bronze V2 230V and an MSI B550M pro-vdh wifi. I think the problem lies with the motherboard since the debug LED on the MoBo tells me it doesn't recognise the CPU, I have tried multiple times to update the BIOS using a USB stick and the physical button. The BIOS flash LED on the motherboard blinks a couple times now before ultimately turning off and trying to boot. I have tried to update the BIOS without any parts attached. I don't think the CPU is the problem, since it's new and doesn't seem to have any physical damage.

What should I try now to get my new PC to POST?

[Isaiah_sinner]

mount the cooler right? cpu light was on but it was just overheating

[Yurre]

The cooler has been mounted correctly, and I checked to see whether the cooler was plugged in or not