Seems to be no other option than have Nikon replace it.
That is, if it isn't just a question of a loose wire or something (in which case, how are you going to find it??).
HOWEVER, the cost of replacing an LCD, what with the labour costs involved may simply not be worth it -- it might well work out as a quarter or more of the price of a new, and better (more advanced) camera. That's the price of our throw-away society, and the ever-onward march of technology. It's both a blessing and a curse -- but when you can get 12Mp cameras for as little as US$350, which even allows Hi-Def video filming, who would really object to ditching a five-year-old lo-res camera, which has done good work, but is now superceded?
Martyn Green, January 2010