Samsung 46" LED smart TV Display Black with sound

My Samsung LED smart TV is 3 years old, recently I notice half of the TV screen turns black but still can see picture but very dark and remaining porting is OK

Service person visited and informed Display panel has gone wrong and needs to change the complete Display panel which cost almost half of the TV cost

Can any one suggest me for this problem (TV screen turns black) do we have change complete Display panel?

I heard if we change the LED lights on panel instead of changing entire Display the problem will be solved

Can any one suggest or guide me best possible solution

Do I need to change my TV Display panel or is there any simple solution