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 TVwill auto sleep.
Remarks : This function is not available in all models.
Please call service when your TV not ok after above operation.