There is a fuse in the TV set, if you would like to check and see if it has blown, here is a way you can do it:
1) Unplug the TV's power cord from the wall
2) Take the back off of the TV by removing the screws and slowly removing the back panel.
3) Look for a component that looks like a glass tube with metallic caps on each of the ends, this will be the fuse.
4) Visually inspect the fuse to see if it shows signs of being open (Blown) These signs are burn marks inside of the glass tube, an open conductor (wire) inside of the glass tube, or no visible wire inside of the tube.
5) using a multimeter set to resistance (R x 1) test the fuse for continuity (remove and change the fuse if found to be defective)
6) If the fuse is not bad, reinstall the fuse if removed, put the rear cover back on.
Now at this point we have determined if the problem is a fuse being blown or not, if you replace the fuse and the TV works great the problem is solved, if you replace the fuse and it blows again, or if the fuse was ok to begin with, then you have a problem that will require some knowledge of electronics pass the basics to continue on. At this point I would suggest that you call a qualified TV repair technician to troubleshoot and repair the TV in question.
I hope this helps,