I am dealing with the same problem. I was given a Presario 700us Notebook and it would not power on. Only lights. the owner replaced the battery and still nothing. I saw a post elsewhere that said something about parts working loose inside. It suggested dropping the computer about an 1inch to see if it helped. I could not bring myself to drop the system so I just gave it a light wack on the bottom and "bamm" the thing now works. Right now I am working on taking it apart to see what had come lose.
techietrooper
February 2007