Tv has sound but no picture. I was watching tv and the picture just went off but the sound is

Question

I was watching tv and the picture just went off but the sound is there. I unpluged it and re-pluged it and it was still the same. I have cable on it, so I disconnected the cable, turned the tv off and waited several minutes and turned the tv back on yet still no picture but there is sound. Cannot access the screne menu, however the remote changes channels and increases/decreases the sound ok. Please help!