b550 a gaming

Hello Yesterday after installing a new PSU and GPU my PC won't boot up. After 5 hours of troubleshooting with a PC hardware fan friend (who built dozens of PCs). We unplugged everything then piece by piece reconnect, in the process I asked him to try jump starting the 24 pins cable, he did it...

Ryzen 5 5600x XFX AMD Radeon RX 5600 XT 6GB GDDR6 Thicc III Ultra ASUS B550-A Gaming Corsair Vengeance 2x8gb 3200MHz 970 Evo Plus 1tb X2 Corsair PSU 650watts Hi, I got a new mobo, ssd (m.2), and CPU upgrades and am having some issues. I'm using old but definitely serviceable parts from my first...