Quasar SP-2719 27" TV "picture goes black flatscreen" Questions

...picture tube seems to go off. It goes black and there is a tiny bit of light in the center for a split second, like the power is being turned off. At the same time, the audio remains, but diminishes ...

...picture or it comes & again it goes....if it is happening like that then following is the situation..........after 4 or 5 yrs in some TVs on main board ( also on CRT circuit board ) at some ...