These power supplies are available just about anywhere, probably even walgreens! J/K but they are very plentyful. Im still using the original and have replaced the battery once.
Have you replaced the battery? In these laptops the battery is an integral part of the system. Mine would not boot with a bad battery.
My father tripped and stepped on his power cord going to the restroom late one night. I came over and swapped out his AC adapter for a new one purchased on Amazon, but his battery was done. It would not boot with his battery in it. Once the battery was removed, his laptop then booted and worked fine. He definitely shorted something when he stepped on the power cable. Just lucky he didnt break the pin in the power connector. His laptop now works fine, just minus the battery.