First, try a reset. Unplug the power cord for a few hours and try again.
Second, try the jiggle and wiggle test; just shake the set around or bang it with your fist to see if the cause is from a loose connection. Wiggling and jiggling the set can often wake up a bad internal connection or cold solder joint.
You can 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 technician service website: www.tvrepairjacksonvillefl.com
jacob
November 2012
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix televisions.