lcd 17″ dell monitor works for 3 seconds then goes blank

if anyone has a solution to this problem let me know

the monitor comes on for about 3 seonds then goes blank

I’ve tried to get into the monitor’s menu to reset it to factory specs, but after 3 seconds, the screen goes blank

I’ve tried turning on the monitor without the pc powered, it said it was in powersaving mode and to press any key, then went blank after 3 seconds

any suggestions? I don’t see an external reset button