My Inspiron 17R 7720 SE has a display screen issue. From time to time there will be a horizontal grey bar around 1/4" tall that will roll from the bottom up to the top of the display and then disappear. At other times the display will cut to a grey/white blank screen that kind of "vibrates" between medium grey/white and light grey/white. This glitch may happen randomly or if the computer is moved or jarred. If I shut the lid or press the power button to hibernate the computer for a minute or so and then wake the computer up, it will resume with a proper display exactly where I left off. It may run a couple of minutes and repeat the glitch, or it may run the rest of the day until I shut it down without a problem.
I ran the F12 startup diagnostic routine which indicated the display adapter was performing normally, so I'm guessing/hoping this glitch is a display screen issue and not a display adapter issue. Has anyone else encountered this issue and identified the problem? Are there any more diagnostics I can run to isolate if this is a display screen or display adapter issue?
The video cable (the one that runs between the mainboard and back of the screen) is the first suspect -- replace that. If it doesn't solve the problem, and the fault doesn't appear on an external screen, the next part would be the display panel. if the fault DOES appear on an external screen as well as the internal one, the GPU is bad - replace the mainboard.