Step1: Check if you set the time in the clock menu on time.
Reason: TV will be switched on when the set on time reach.
Solution: Cancel the on time that you set.
Step2: Check if you set the time in the clock menu-off time.
Reason:TV will enter standby mode when the set off time reach.
Solution: Cancel the off time that you set.
Note:Within 15 minutes there is no signal, the TV will auto sleep