While on a channel - input 8282 on remote , that will take you to menu page that has the 'set default key' option- just select it. Exit out of menu and hopefully you soon will have picture.
HELLO I'M HAVING THE SAME PROBLEM, MY 3500 WAS WORKING AND ALL OF THE SUDDEN THE BOX SHOTDOWN AND I GOT SRAMBLED CHANNEL AND THE TV WILL NOT COME BACK UP . I TRIED WHAT YOU SUJESTED ABOUT THE DEFAULT KEYS AND NOTHING I WILL ALSO APPRECIATE ANY HELP OR SUGGESTION THAT ANYBODY CAN GIVE ME. THANKS I ADVANCE.