BOOT Error (Yellow Green LED mark)

[Fadinq01]

Context:
Today I began a new pc build using my previous prebuilt components (case, psu, case fan, cables, SSD, HDD) but couldn’t progress farther than the bios screen. I launch my pc using various methods and it immediately enters bios and nothing else. I look at my Flashback LED and it glows a yellowish green (meaning BOOT error). I need help (hopefully without needing to take everything out because I have little holiday time and it took me forever) asap. Thanks!

 

Confirmations:

BIOS works.

Power cables are connected and give power.

All listed components seem to work.

 

Components:

Monitor & Mouse & Keyboard

(Detected and works)

RAM = Corsair Dominator Platinum 2x8GB 3600mhz

(Detected and works)

CPU = AMD Ryzen 7 5700G

(Detected)

GPU = None

Motherboard = ROG Strix B550F 

(Works)

Cooler = Noctua NHU12S (Detected and spins)

HDD = Toshiba HDWD110 (Detected)

SSD = ADATA SU630 (Detected)