Question I need help

[Titas55]

so i had a really old power supply and it was super loud and smoke started coming out of it so i decided to swao it with my other computers supply power supply unit and i changed the gpu so once i plugged everything up everythings smooth and quiet fans are spinning but there is no display and i tried taking the rams out but there is no beep and i need help do i need a nee power supply or what or a motherboard

 

[rgd1101]

full system spec? include make and model of the psu

 

[Titas55]

psu : delux switching power supply atx-420w p4
pc : geforce gtx 750 ti 8gb ram i3 4th gen

 

[Titas55]

Could it be a dead battery?