I had a similar problem with a dvd player,I could get the display to come on, if I tapped around the screen lightly. This led me to believe that there was a loose connection on a component inside. I took the screen apart. I had to remove 4 screws which were hidden beneath rubber plugs on the screen case,they popped out when pried with a pin. I then ran a straight blade screwdriver around the crease of the top case,it unlatched about every 2 inches. I could then remove both halves of the top case. I then tapped with the end of a Q-tips around the circuit board inside. I found a place where I tapped, that would get the screen to come on. I had a dvd playing at the time inside the unit. I then shut the dvd player off and examined the circuit board. I found a component that had a bad solder joint on one of the legs. I then resoldered the component leg back to the circuit board and PRESTO the display worked when I applied power to the unit. I don't know exactly what the component was,but I have worked on other electronics and have seen similar problems with bad solder joints. These can drive you crazy because sometime things will work until the solder joint gets hot and then stop working because the component expands and moves away from the solder connection. This problem would have been easier to fix if a set of schematics were available to show how the backlight circuitry and components were located. I hope this helps you and good luck!
John N.
November 2006