You need the capacitor fix
Samsung does what they call a capacitor fix for free no matter how old is TV since it was a design flaw in that the capacitors used in the power supply were under capacity for the application.
You need only call Samsung on their 800 number and tell them that you need the free capacitor fix for your TV and they'll arrange it for you.
In my case they came out and fixed it the same day I called. It was done in 15 minutes and they changed 3 capacitors on the power supply.