A TV that fails to power on after a power outage is not an uncommon problem for the home consumer to encounter. However, this does not always indicate a catastrophic problem with the TV, and you can often restore power and full functionality to the TV with some simple and painless home troubleshooting. You can save money on costly TV repair or replacement and time on the phone with a Panasonic customer support representative who is going to walk you through all of the same troubleshooting steps you can do on your own anyway.
Check the AC power cable for any looseness or damage. Whether plugged into a standard electrical outlet or a surge protector, the power cable's loosening even slightly can prevent the TV from powering on. If you use a surge protector, make sure it was not powered off during the outage (if so, power it back on). Also, make sure the other end of the power cable is not detached from the TV, as many Panasonic TVs are built with this feature. Try powering on the TV again.
Plug the power cable into an alternate electrical source. Another common cause of this issue is that an electrical outlet or surge protector was damaged during the outage and now is not giving any current. Plug the TV's power cable into a different electrical outlet, a different surge protector, or simply bypass the surge protector and plug the cord directly into an outlet. Again, try to power on the TV to see if this resolves the problem.
Contact Panasonic technical support. This is probably the extent of the troubleshooting you can perform on your own if the TV still does not power on at this point. Contacting Panasonic is a good step here because the TV still may be under warranty and you may potentially save money of having the TV's power cord or the TV itself serviced or replaced.