Disclosed are a display apparatus, system and control method , the display apparatus including a communicating unit which performs a communication with an external tuner, and receives an intermediate frequency (IF) signal from the external tuner; an IF signal processing unit which processes th e IF signal received in the communicating unit; and a control unit which controls the IF signal processing unit to process the received IF signal to be a signal displayable on a display unit if receiving the IF signal from the external tuner.