Hi, my son dropped my laptop 1 inch from the ground the other day. and the next thing i know when i switched on my laptop the screen is dim and there's light flickering (you need to focus on the screen long enough to realize the flickering). I have tried brightening the screen using the adjusting key (f3 & f4) but it does not work. I have also run a test on the hardware to see whether there's any malfunction as a result of the drop but the test is passed and no problem surfaced. HELP!