computer was not touched when it happened the first time,was just powered on and left alone & i heard it powering down on its own
That was the old faulty PSU you had replaced
Still worth checking you didnt miss anything when fitting this new psu up
My last build i did i forgot to connect my pump upto the molex and the system
did the same as your problem,just quick blink and shutdown when i tried
powering it up.1st thing i did was check my connections which i found the pump connected it up and bam all is good