I have an HP Touchsmart 310-1125f all in one pc that will not display anything when turned on. I can hear it boot up and the fan running and the power button light is on but I get nothing from the screen. When I plug the power cord in the green light next to it turns on and the blue power button light blinks three times. When I press the power button it all sounds normal, it revs up, the cd drive clicks, the hard drive buzzes and fan hums. But the screen does not turn on. To turn it off I have to hold the power button for five seconds.