Your power supply is going to have issues in one of three places in your camera; either the battery, the contacts themselves or the power supply internally may have failed. We can work on the battery and contacts, but if the camera still doesn't turn on, then you would need to take it to repair for a possible circuit board failure or replace.
You've already charged your battery and tried it. This rules out your battery being the problem.
Sometimes you can have a power failure if there is a little dust or grit is compromising the connection from battery to camera. It really doesn't take much to cause a problem, so cleaning could solve this issue.
Take a cotton swab moistened with a little bit of alcohol and wipe the contacts in the camera's battery compartment until shiny clean. Take a pencil eraser and rub the contacts on the battery to remove any dust or other coating that may be there and then make sure to brush all the rubbings off. Replace the battery and test. This will rule out that dirty contacts are the issue.
If cleaning doesn't work, then it's time to have a technician physically examine the camera for a circuit board failure. If you would like me to help you find a local repair shop I'd be happy to assist. I would need your zip code to do this search for you.