|It sounds like your display, or your laptop otherwise, is DAMAGED.|
Have you, or is it possible someone else who had access to this computer...
- dropped it, or dropped anything on it, or otherwise exposed it to a physical jolt ?
- spilled liquid on it, or sprayed it with liquid, or exposed it to liquid such as rain ?
Since the video last worked properly all the time, has there been a power failure event that happened while the AC adapter was plugged in ?
Those things are the most frequent reasons something inside the laptop has been damaged.
In any case, your symptoms probably cannot be caused by a software problem.
Try connecting an external monitor. If there's nothing wrong with your video adapter, the display on that will be fine.
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.
Your symptoms could be caused by overheating inside your laptop case, but in that case you would only get the symptoms after the laptop had time to warm up, and you would likely have problems in Windows as well just before you got the symptoms.
E.g. overheating can be caused by
- failure of the fan inside the laptop case (it never spins anymore)
- or obstruction of the air passges into / out of the case on the exterior of it (e.g. don't use it on bedsheets, or on loose clothing on your lap)
- or obstruction of the air passages inside of it