Hi dogsport, welcome to AH.
Is your TV plugged into a surge device, or power conditioner?
If not, I'm wondering if you caught a power spike.
Try unplugging it for a few minutes, and plug it back in and see what happens.
Saw this on their site:
1. press the main power switch located in the lower left corner of the Plasma.
2. Press the Stanby/On button, either using the remote of the button on the right side of the panel.
If the unit still does not power on, please contact our Plasma support at 1-800-421-1625.