Why does my on-screen program Guide show "????" when I tune to a channel on the Guide?:
If you attempt to tune to a channel that doesn’t exist, the on-screen program Guide may display “????” instead of a channel number. You can set the Guide to tune the next highest channel with these steps:
Press the SETTINGS button on your remote.
Scroll right to Display.
Scroll down to Nearest Tune.
Press the SELECT button to toggle setting from OFF to ON.