Pc not posting

[Benis23]

So last week i bought me some parts and built the pc then when i powered it up all the rgb lit up but nothing showed up on the display and then me and my dad got it to work somehow but then it did it again yesterday but now i tried everything and nothing helped it still doesnt post (Pc parts, mobo: Prime X670-P wifi, Ram: Kingstin fury 6400mhz, Cpu: AMD ryzen 9 7900X3D, Gpu: Rtx 4070, Power supply: corsair 750w 

[emosun]

47 minutes ago, Benis23 said:

but then it did it again yesterday but now i tried everything and nothing helped

did you want to tell us what you've tried already?

[Benis23]

43 minutes ago, emosun said:

did you want to tell us what you've tried already?

Tried the stick of ram alone(both), reseated the cpu, cheked all power supply connections, reseated the gpu, reset the cmos.

[Milesqqw2]

Make sure all of the cables from the psu are connected fully. And see if you can flash the bios.

[Benis23]

15 hours ago, Milesqqw2 said:

Make sure all of the cables from the psu are connected fully. And see if you can flash the bios.

It has booted before and i have played games fine bu then it happened all of a sudden