I had problems with my DC input. It was solved by tightening up all the case screws along the back of the laptop and screen.
dms05
November 2007
You need the Service Manual. I bought one off ebay uk for £1.99. Mine covers the Aspire 3000 and 5000 series but they seem to be available for almost any model. The manual was emailed to me in pdf format. Well worth the price. It shows pretty well all the details on how to dismantle the laptop and runs to well over 100 pages with pictures and diagrams.