Hello! I have lost contrast on my Reprapdiscount 12864 LCD display connected to my Ramps 1.4. I can see the graphics really really faint. Everything else works and I can navigate and drive the stepper motors on my CNC. BUT! If I connect a ordinary USB cable to the Arduino Mega from my computer, I get contrast and everything is as normal... But not with my regular power cable adapter. How do Iby DailyBombs - RAMPS Electronics