It took me a while to finally find out how to access it to determine this, but here is how.
- On the TV itself, hold down the "Vol -" Button
- While holding the volume button down, press "info" on the TV remote three times. Wait. Depending on what mode you are in, you will notice the display change. Two blue windows will appear in the upper left portion of your screen. This is the service menu. Keep reading if you want to know how to determine the number of hours on the set.
- Now press the "2" button on the remote. This will pull up a window with the word "SRV-TOOL"
- Press the "OK" button on the remote. A light blue grid will appear.
- On the Grid, cursor down (using the remote down arrows) to the row labeled "PTCT"
- Cursor to the right. It should be an empty box.
- Hold MUTE for 3 seconds. The amount of time the display has been on will be next to the word "TIME" this is in hours and minutes.
To get out of the service menu, I just power cycled the TV by holding the power button down on the TV itself. I hope this helps some people. It took me a while to find this and actually figure out exactly what I needed to do. If it helps you, leave a comment!