screen is black but sound is fine

RCA L32H41 TV screen is black, but sound is on. Netflix and HBO Go have picture, sound everything perfect. I have tried unplugging TV power cord from wall and waiting, plugging back in, that doesn’t work. Unplugged power cord from back of TV waited and then plugged back in, that didn’t work. Unplugged power cord from digital box, waited 30 sec., and when all the functions are back in indicated by lights, still didn’t work. Turn TV off and on, didn’t work. This happened once before and mediacom repair came over and there had been a black out. He unplugged the power cord from the back of the TV and then plugged it back in and it worked, but it hasn’t worked this time. I also pressed the volume button down on the TV at the same time I pressed the clear button the remote, waited 5 sec. and that didn’t work either. Help!?