Pixelation

Question

I've had my Vizio 42" plasma tv for a couple of years. I bought it at costco over two years ago. I see little red dots when ever there's something black on the screen or the scene itself is dark.It looks like lightning or a red silver lining, like pixelation. I payed a couple of thousand for it so scrapping it is hardly an option. What is the fault with the TV and can it be repaired.