I am using Dell Latitude E6440 laptop from last four months and flickering problem started in the last week. It is so weird that I can't even read. It works fine with external output device (TV). I tried to find Ambient Light Sensor setting after checking various forums, couldn't find it in BIOS and 'Left Arrow + Function Key' is also not working. Problem occurs with or without A/c adapter. Machine has got Intel HD Graphics 4600 card.
Tried disabling 'Power Saving Technology' in Intel Graphics Power options but no success.
I have also downloaded recent updates from Microsoft, Dell and Intel.
Downloaded recent Video drivers compatible with Laptop.
Still could not solve this problem. Can you please have a look and let me know your opinion please? Thanks!