I have a hp dv6000. My son closed the lid firmly. Next time I booted it, the screen had wavy lines on it. Sometimes its hard to read print (especially color on color).
Sounds like a graphics card problem? Does your laptop use a NVidia Graphics card, I know HP had allot of problems with NVidia graphics cards heating up and failing in there DV machines and I know for a fact the Dv6000 was affected by this issue.