The exact problem as mentioned in the Title appeared out of the blue one day and all the text and images on the screen of my Macbook Air 2015 are beyond comprehension as the screen is constantly flickering. The level the texts and image is getting burned is beyond comprehension.
I had tested with a mini-monitor to VGA connector on an external monitor and I get a flicker-free stable display on the external monitor.
Does that imply the flex cable that connects from the logic board to the monitor is faulty?
I have tried SMC reset and NVRAM/PRAM reset but that did not solve the issue.