Foergive me if this is a red herring - I can't be arsed to do a full search of the forum; but wasn't there a thread here where a so called "magnet piece" was becoming detached from its solder point on the motherboard and basically falling off onto the casing?

If it wasn't the same laptop - I'm sorry. But it's wotrth a look around the forum or a look inside the laptop for something loose. It's this pressing in the corner that's the clue - it appears to help make a circuit so something could have come adrift.

Me - I'm a Dell man/family for laptops! Ne'er a problem in 8 years and about 6 laptops passed through the family.