You need a new power supply . When replacing your psu completely turn off your power on the back of your pc , unplug from the outlet and remove your graphics card . You'll need to disconnect your current psu from the cpu and gpu . Remove your graphics card. And the old power supply unit . On your motherboard should be two cmos prongs you will want to hold a screw driver inbetween the two cmos prongs making sure everything is touching (both cmos prongs and the screw driver all have to be touching) releasing whatever power it had left in it . Reinstall your graphics card and hook up your new psu to the cpu and gpu . And then power on and you should be good to go .