Hello. My mom shares a room, with another resident, in her facility. Often I'll arrive to find that the TV isn't on. Someone keeps turning off the cable box. So I'll turn the cable box on, using the remote. Then I'll try turning on the TV, but I just get a "snowy" picture. Her roommate's remote control is the same as my mom's and works my mom's TV as well! I don't think there is anything I can do about that, but what I need to know is how to I clear my mom's picture?