your picture tube is going bad its blinking because one of the colors r/g/b is weaker than the others you can restore the tube or up the heater voltage by raping a wire around the core of the flyback 3 times then disconect the filments from the tube then solder the 2 wires from the flyback to the board where you disconected the wires from the board from the chassis that will make the fiilment voltage higer then your picture will look better and it wont blink or you can buy a new tv bye 4 now