First check your wires and make sure they are not running for long distances next to high current wires. You may even want to isolate the LCD Panel's wires just to test for electrical interference by removing the LCD Panel from the machine and getting every thing connected to it away from other wires.
And if that doesn't resolve the problem, you may want to spend $10 and get a new LCD Panel. There have been a noticeable number of complaints about faulty graphical LCD Panels lately.
And if that doesn't resolve the problem, you may want to spend $10 and get a new LCD Panel. There have been a noticeable number of complaints about faulty graphical LCD Panels lately.