When my TV is turned on, the horizontal line will not hold and the image is duplicated. Initially it only rolled for 2 minutes or so until it was "warm." Now it has a double pic and rolls virtually all the time, even after hours of being powered on. At times it has a normal picture but this does not last for very long. I would like to know if it can be fixed. This television is about l2 years old. Thanks in advance.