I have an older Dell Latitude D830 and just replaced the screen last night! Before you ask....yes I have connected to another external monitor and colors, wavey lines, etc are NOT there. Immediately after replacing the monitor screen everything was back to normal...colors were great, no squiggly lines...HAPPY, HAPPY! However after about 20 minutes the colors became distorted again and yep...you guessed it...here come the wavey lines.
I'm no computer tech but I was wondering if this problem has something to do with the LCD Coxial cable that are used on the back of the monitor. It's almost like the longer the computer is powered up, the worse my screen gets. Something overheating????
Greatly appreciate any help, ideas, etc