1. Black lines appear on the LCD TV screen. If the position of the line changes, it may be caused by the problem of the TV signal source or the program source. Black lines; if the connection line is loose, it can be fixed, or you can change the connection to the connection and try it again. If it is the problem of the program source, you can switch to other program channels for viewing testing. 2. If it is determined that it is not a signal source or a program source, it may be caused by the fault of the TV hardware, which is mainly screen cable failure or poor contact, display screen failure, internal circuit failure, etc. After the after -sales service, it can be resolved in a comprehensive maintenance.