Some Dell and Gateway powersupplies have problems after power surges, power outages and all other power disruptions. If a dell computer is shutdown wrong by most reasons when you turn the power back on the video won’t iniatialize and the system will not boot up. You will see nothing on the screen but you will hear the power supply fan and all other fans on. You won’t hear the system boot up either. It is a problem with resetting some internal switch for the power supply. To resolve this unplug the power cable from the back of the unit, wait about 5 seconds then plug it back in. Before you do this, if it is a ATX power supply make sure you flip the switch on the back to off first. Plug back in and flip switch and power up. It should boot then.