If you research this.

by R. Proffitt Moderator - 12/24/10 7:38 AM

In Reply to: How do you turn on the 120Hz? by clockhart33

The on screen display is showing the signal source which will always be 60Hz. Sadly the makers didn't explain what the 120Hz is doing and folk are asking YOUR QUESTION repeatedly.

Google this and find the repeating answer. It's far too long for me to type it in every time it comes up.
Bob