PC wont Start After adding a new part

Badguy11

Honorable
Oct 15, 2016
18
0
10,510
So my PC wont boot whenever i add a new part or clean it. for example, yesterday i bought an ssd , after adding it to the rig it wouldn't start. Fans spins , Led turns on but computer wont show display, no beep, nothing.
it happens every time i add or remove any of its parts, eg replace hdd/ssd, or ram etc
each time i try the old fix it wont work.
last time the way i fixed it was by re-plugging the wires to mobo
Actually i didn't build this pc at once, i add new parts from time to time.

What could be the reason?

Specs
i5 6600
Asus z170k mobo
CM elite v2 550 PSU
Corsair vengeance 8gb ddr4