RCA picture problem

I have an older model projection tv that the picture went out in.  The model is p56720lv and I can't seem to find any help anywhere.  For a couple of days the picture would suddenly go out then come back.  Now it went out for good.  Does anyone know if this could be the picture tube.  Nothing is lighting up except the front power button..  I have static sound and that is all.  HELP