More than likely it is the power circuit board on the tv that is going out. You can call or email the manufacturer and see what they say. If you do not have any factory warranty, asked for a cost estimate of the repair. It might not be cost effective in repairing than just buying a new tv. This is a common issue with lower brand tv. Go online to Home Theater Magazine and read the reviews on tvs, along with the pro and con of each technology.
I give you a tech website (www.tvrepairjacksonvillefl.com) if you need to contact with a technician service.
abel, August 2012
