Are you willing to get your hands dirty to save a bit of cash?.
I reckon that what you have is an intermittent connection on one of the connector strips (as in wires).
It sounds like it is out of warranty, so what do you have to lose?.
Get your multimeter and test each of the wires for continuity while shaking the laptop.
My guess would be either a bad wire link between the bottom part of the laptop and the screen or a "dry-joint" on one of the PCB's.