Question My newly built PC is not booting

[ryanego285]

My PC fans are turning on only for a second, but the rgb lights on the motherboard stays on, but the q-leds are not turning on. The monitor displays that no signal exists.

Parts list :
Mobo : TUF gaming x570-plus (WiFi)
GPU : TUF RTX 4070 OC
CPU : AMD Ryzen 9 5950X
PSU : Corsair Rm850x

 

[ilukey77]

Two cables go in there:

EPS 12V 8pin (4pin+4pin)and​

ATX 12V 4pin​

its funny how something so simple can be overlooked sometimes !!
like my turning the psu off trying to boot the pc then turning the psu on and unplugging everything re installing everything then turning the psu off no boot took me about 2 hours till i figured what i was doing wrong