I have a laptop running windows 10 with an i7 processor and Intel HD Graphics 5500. The main display on the laptop refuses to turn on when I boot up the system now. About 1 every 20 times I try it'll work until it goes into sleep mode, and then I have to start the process over to get it back on. All of the drivers are updated and rolling back the graphics driver achieved nothing. It seems to work when connected to an external display, but it won't even recognize the laptop screen as a display output. It's definitely not the back light because it DOES work every so often. Any ideas?