My screen has vertical colored lines and vertical wide white lines down 1/4 of the screen. They appeared suddenly while I was surfing around. The closest documented problem I have found is described here: http://support.apple.com/kb/TS2376 (Summary--After updating to Mac OS X 10.4.7, the MacBook may show a solid grey, white, or black screen or a screen with vertical multi-colored line).
I have v. 10.5.5, followed the instructions anyhow for resetting the NVRAM, but nothing worked. Apple hardware test is normal. The computer is 3 months old, does not have Apple Care. It has not been bumped, dropped, sat on, etc. The screen looks physically normal.
Any suggestions on what the problem is and how to fix it? Thanks in advance!