|That CANNOT be caused by a software problem. |
Either the display assembly is damaged, or the wiring between the display assembly and the video adapter is damaged.
Usually there's nothing wrong with the video adapter. Try connecting an external monitor to it. You will probably find there's no problem with the display on that.
Laptop no video (or video problems), and battery, AC adapter, power jack T shooting.
See response 1:
DO NOT plug in or unplug a monitor's video cable into / from a video port while the computer is running. Doing so can damage the monitor's circuits and/or the video adapter's circuits.
Some laptops will display on an external monitor without you having to do anything.
If you get no video on an external monitor, some laptops have a key combo that you must press to toggle the display to external video only / built in display video only / sometimes both - see the Owner's or User's manual for the model (e.g. press both Fn and Fx ; x is a number).