PC won’t start.

[king1]

first thing to do is put everything back as it was when working, old cpu old ram old psu. Get a definitive "something is now broken" or "one of the new components caused the problem"

EDIT: At the same time you should generally troubleshoot one at a time so if you confirm it works ok with the old hardware then swap out either the CPU OR add in the new RAM, one or the other could be the problem. Mismatched RAM can be incompatible...