I�ve had this happen a few times and as Dellgirl says, check the fuse first - probably wont be the one in the plug.
If you�re competent enough then whip the back off and if you follow where the power cable goes then somewhere within close proximity to where it �connects� inside you�ll see a small clear fuse (not a normal household one) which has probably blown. You need to buy these from a TV repair shop (c.35p)
If in ANY doubt about your ability call the in pros though, and obviously make sure it�s unplugged before attempting anything!!