Blank screen with sound and backlight the first time I turn it on,

I have a Vizio P602ui-B3. When I turn the power on the first time, I get sound with backlight, but no picture. If I cycle the power off, then back on again, everything works normally. I also noticed the “power on light" seems dimmer, the first time it is turned on, but not the 2nd. I have completed the power reset instructions, with no difference in symptoms. Thoughts, ideas welcome!