Samsung PN64E8000 manual Channel menu is only available when you select the TV source

The Channel menu is only available when you select the TV source.

Your settings are lost after 30 minutes or every time the TV is turned off.

If the TV is in the Store Demo mode, it will reset audio and picture settings every 30 minutes. Change the settings from Store Demo mode to Home Use mode using the Setup procedure. Select TV in the Source using your remote, and go to System → Setup.