Dell Inspiron 9300 LCD went black

Hello,

My 4 yr old Dell laptop has been a rock solid dream performer its entire life. Today for the first time the LCD showed something like a watermark on the wallpaper along the upper edge from about 1/3 from the left and across to the right edge. Later in the day the LCD began to shadow flicker along the right side. Narrower at the top and bottom, kinda bowing in to the display. This seemed to happen when the power demand, cpu and memory usage increased. It came and went a few times. Three hours later it re-appeared then a thin vertical black band traveled from right to left across the screen followed by a solid wall of black moving from right to left and the entire screen became black and still is. I unplugged and let it sit. Started it up and it is still black. Plugged in an external display and everything works on the new display while the laptop display is black. Please help me find a solution I'm not quite ready to pay for a new laptop yet. Thank you