[SOLVED] New Pc Build (Keeps on rebooting and no display)


Hello, my friend built a new rig and he has the problems as stated in the title. His pc doesnt boot to bios and keeps on rebooting with no display. He already reseated the ram. Tonight, i'll have him recheck the wire connectors. Besides that, any other suggestions? Oh yeah also, his mouse and keyboard lights up when plugged into the pc.
The rig is as stated:

Asrock b450m steel legend
Ryzen 5 2600 with stock cooler
Kingston Hyperx Fury 8gb 3200mhz x 2
Zotac Rtx 2060 Twin Fan
Corsair Cx550m grey version
Silicon Power NVMe PCIe Gen3x4 M.2 2280 SSD 1tb


Well i think i've fixed it but im not sure how. Below are the steps that i took.
  1. Reinstalling the gpu
  2. Reinstalling the ram again
  3. Reconnect the cpu and motherboard power connector
  4. Quite unlikely that this was the issue but the hdd led front panel connector polarity was connected in the wrong direction so reversed it back.