Chosen Solution
May I know would it be the monitor / display card / the cable damaged? And how to fix it ?
Ouch! Your display was damaged. A good bang or something heavy sat on the lid damaging the panels connections. The easiest way is just replacing the full lid assembly 13” MacBook Pro Complete Display Assembly, Apple P/N 661-6594 If you’re more skilled you can replace the LCD panel 13” MacBook Pro LCD Panel In any case you’ll need to follow this guide to get the display disconnected MacBook Pro 13" Unibody Mid 2012 Display Replacement and if you decide to replace the panel follow this guide [MacBook Pro 13" Unibody Mid 2010 LCD Replacement. There some small differences so take note not to force things.
