Why sometimes a popping or cracking noise comes after I turn off my TV?

Samsung Televisions use a combination of metal and plastic material in their sets. These materials are subject to expansion and contraction due to temperature changes. With expansion or contraction you may occasionally hear popping or cracking sound. These noises are completely harmless and will not affect your TV’s operation or damage the unit. 

( Popping noise in TV )

● The popping or cracking noises you hear after you turn off your TV are caused by different parts inside the TV contracting as they cool.

● It is caused by the thermal expansion the metal chassis of the TV goes through during the warm-up phase. These sounds are normal, and happen in a variety of different enviorments.