Televisions of any brand can experience any number of technical issues, up to and including a failure to power on at all. Before spending any money on expensive TV repair or an even more expensive new television, do a few simple troubleshooting steps on your own to try and restore power to your television.
Verify power cable has not come loose by tracing it to the electrical outlet or surge protector into which it is plugged. Replug the power cable if it has come loose at all. Sometimes, TV power cables can also be unplugged from the TV itself. If your TV has this type of power cord also verify that it has not come loose from the back of the TV.
Plug the TV's power cord into a different slot on the surge protector or a different electrical outlet to test for a possible issue with the surge protector or the electrical outlet.
Contact Panasonic technical support or have the TV serviced if it still does not power on at this point.