My Toshiba Color TV manufactured in 1999 has no picture but I hear the sound just fine. When I shake it it has a white line across the screen but that only comes when I shake it. It's a 15 t0 20 inch TV I believe.

Sounds like the electron gun is shot, or more specifically the magnets that aim it. It needs to be repaired, but these days it will probably cost less to buy a new TV.