I have HP Pavilion DV4T-2100 model running windows 7. Today when I turn it on I got black screen and it is not showing anything at all. Everything else is working. I can hear fan noise, LEDs lights are blinking and even I can hear window welcome tone when window starts and also as I know my first screen is password screen when that tone is played I type password and press enter and I can hear sound that is played when user login inside system. Only thing that is missing is display as screen is completely black all time. I have done removing battery and pressing power button for 30-60 second…