nanohex:
This may seem like a noob point, but I noticed your PCB doesn't have a ground flood? You should try adding one in to aid in heat-sinking!...apologies if you already know this
@liudr, I added the cap at LCD Vdd and Vss. Unfortunately the problem still exists. 
I will try cleaning up all the wiring and solder joints.
@nanohex, would you mind clarifying the ground flood for me? I am not too familiar with it. Thanks.