Yeah, sounds like your TV isn't working right. Like Member Assist said, I would call to see if you bought the Sears Protection Plan with your TV. If so, you could get Sears to come out to your house and try to repair your TV. If not, then you would get a code and an amount of money to go to Sears and pick out a new TV, and the remaining amount of Protection you had with Sears will roll over onto your new TV.
If you did NOT get the protection with your TV, then you will need to contact RCA and see on how to go about getting it serviced and fixed. It will need to be under the 12 month warranty time frame, you will need proof of purchase, and most likely based by the size they may make you ship it to them at your cost. But you will have to talk to RCA about that,
RCA - 1-888-977-6722
Sears - 1-800-573-1088