not sure but it might be your capacitors. if your tv is not under warranty, you can fix it yourself. a quick removal of the back panel can show you whether the caps are good or bad.
If the TV is under warranty, have it repaired. Otherwise, call the manufacturer helpline and ask them how to diagnose the problem. You can also call a local TV repair shop for an idea of what is going on and what it would cost to repair.
Here you are a tech service website www.tvrepairjacksonvillefl.com
I hope this help
abel
August 2012