My light panel for the overhead had become warped and the backlighting was not working. A little investigation revealed it was an electro-luminescent panel powered by an AC inverter in the overhead. I checked the inverter power output and it was good. Further investigation revealed several interesting facts. 1. The life span of these panels is about 2000 hours and since the panel is continuous power, if the airplane has more than 2000 hours, the panel is near EOL. 2. The inverter is si