Powerscan:
Turn on your TV
Press and hold the TV Mode button (white tv button at the top of the remote) until all of the mode buttons blink.
Release the TV mode button
Press and release the red TV button
press the up arrow repeatedly (one push per second) until the TV turns off.
after the TV turns off push the # button (at the bottom of the remote on the right side)
If this doesn't work then read the book that came with your STB