My hp laptop zv5000 is not booting?

I have zv5000 since 7 years. It worked fine till Jan 2011 and now it stopped booting.

Couple of times, it booted and worked BUT most of the times it does not.

Is it an issue with the harddrive connector that connect to the mother board?? I tried replacing the connector but did not work. It botted 2 times inbetween but not always.

Did anybody have such problem?? Any Idea or suggestion to try??