Please read this whole post. If you have more questions afterward, just ask. Once you're satisfied and feel you can leave positive feedback about our conversation, please click the green "Accept" button (that's how I get paid). Thanks!
Ok, I understand. Well, everything is reparable. It just boils down to cost effectiveness. So the question is: Will this be cost effective to repair? Maybe.
Without a decent working knowledge of electronics and test equipment (a voltmeter, at the very least), the only thing you can do at this point is unplug the TV for a while. Sometimes these issues are just "glitches" that can be cleared by removing power for an hour or longer (overnight).
If this persists, you definitely have an internal failure here and you will need a technician to take a look. Without making any measurements, it’s tough to say with any certainty what the problem is, but there is a short list of possible malfunctions including the power supply and the main board. It could also be the panel (the screen) but that's typically more rare.
The power supply takes the line input... chops/rectifies/filters it, and sends out a series of DC voltages. A fault here could very easily explain your symptoms, really because it's the base for everything else. Repair here will vary depending on where you live, and on part availability, but usually runs $250-$350.
The main board handles the I/O capabilities and processing. So this could also be your issue. Repair here will be more than the power supply, usually by $100-$200.
So if the unplug doesn’t cure this, consider having a tech take a look. Some diagnostics shouldn't run more than $50-$75, and most of that would be put toward the final bill should you decide to have it repaired. If you’d like, feel free to post back with your zip or postal code and I’ll see if I can find a local repair center for you, ok?Respectfully,Dan