Picture Blinks for Four Minutes. The TV takes about 30 seconds to a minute to show a picture. It

Question

The TV takes about 30 seconds to a minute to show a picture. It then takes at least another 3 minutes to to I guess "warm up" then it will stop blinking. It did this a year ago and then stopped for a while when we got a new cable box. Now it is worse than before. In the last week after it has "warmed up" it blinks once or twice.