I have an a1229
i have had to be careful with it on my lap
MBP is not a laptop. It's a notebook and should never be placed on your lap.
According to the user manual it states in part:
"Do not operate your MacBook Pro on a pillow or other soft material, as the material can block the airflow vents. Never place anything over the keyboard when operating your MacBook Pro. Never push objects into the ventilation openings."
"Do not place your MacBook Pro on your lap or other body surface for extended periods of time. Prolonged body contact can cause discomfort and potentially a burn."
I've been having issues with my charger
Apple Portables: Troubleshooting MagSafe adapters
If you are still under warranty and/or have AC, call them. Let Apple deal w/your problems.
A 2007 MBP may very well have inhaled a lot of dust and schmutz. Open it up and see if there is anything inside that needs to be cleaned out. Taking off the keyboard is a bit tedious but not out of the realm of a reasonably handy individual. You will need a #00 Phillips and a #6 Torx drivers. look at this OWC video for instructions. The 'hard part' is disconnecting the key board.
Bany Boomer: Thanks anyway.
Ogelthorpe: Yeah I've been there. Since I got this I've had apple replace the top case, keyboard, bottom case and display. I've changed the hard drive, left fan assembly and dc in all at different times so I've definately been inside and I've explored about every option. I've also replaced the charger itself and used my wife's. I've replaced the battery twice. I was more looking for the random short etc. Thanks though and i appreciate the effort.