No picture but has sound

My sony tv has sound when you turn it on but no picture.  We have unplugged the tv waited and the picture would finally come up. We called sony support and all they told us is to unplug. this morning when i got up the sound was there no picture but after cutting the tv off several times the picture appeared. now to come back home and have the same thing happen. after cont cutting off and on the picture will appear the sound is fine.  the red light does not blink after the tv picture appears. when you first cut the tv on it blinks then.  please help??? after the picture appears i have cut the tv off and on and the picture comes on its when you cut the tv off for a period of time there is no picture but we have sound.

Picture is gone, has sound for awhile, then the sound goes off as well. When turning on the set the screen is very bright, then goes bright blue, then black. The power light flashes five times, then stops, then repeats. Any suggestions?