Replying to TV Trouble

So, I'm in school now with my new TV. Got it up and running yesterday and it worked perfectly. I got all the channels I needed, and the N64 worked fine on it (although it lagged a bit, anyone know how to fix that?). So, I wake up this morning to turn on the news on the new TV that worked perfectly yesterday. I press the power button, and the orange light starts to flash, indicating it's turning on. Then the light changed to green, indicating that it was on, but there was no picture or sound. The screen was black (the off kind of black, not the on but no picture kind of black), and there was no sign of it being actually on. I tried switching from video mode to TV mode several times to no avail. I looked up the troubleshooting in the manual, which said if there's no power, unplug the cord for 60 seconds, and replug it and turn it on, which I have now done several times. WTF? It was working perfectly yesterday? Suggestions?