I have one of those generic white pcb screen connected to my ramps , whenever i connect the usb to my PC each character position slowely starts turning black until it reaches its max contrast. when i unplug the usb it goes back to displaying the printer stats, if i try and connect to the printer in repetier it never gets a reading from the thermistors after if you unplug the usb so you can see the characters on the display it says err: mintemp.
Ive looked into this and only thing ive found is a comment by someone on another site saying it means the arduino might be going bad, i dont have another one on hand to test so i figured id ask what do you guys think ?