My remote won't work and I used to be able to change the channel on the TV but even that dosn't work. I checked the cords. Changed the batteries;

Hello
First check its battery contacts for any rust or dirt accumulated on it. If so, contacts of battery will not touch properly, and the unit will fail to work. The second reason for malfunction is due to the infrared sensor inside your tV. If it is faulty, the set won't respond to infrared signal generated by the remote control. If so, eventhough remote control works properly, the set won't work with it.
Remote sensor comes just behind the infrared window at the bottom front panel of your TV. It is a replacable part and not so costly too. It is a three terninal component will look brownish black in colour. It will looke like this.

The procedure to check the remote control for its perfect working is described at a tip I've given and published by Fixya on Google. Type "gopakumarg43" on google search box, and get into my profiles. There you can see 'Tips and How To's" line, click on it. You can read it there. OK.