Need Help Toshiba 3377db

Hello, I'm new here and not a TV engineer. I have a 33" Toshiba 3377DB TV. Recently it has done something which has now disappeared but I'm wondering what I should do. I switched it on one day and the picture was fine, then the picture had a high blue tint then I saw no picture, a high blue tint and thin white horizontal lines before the TV switches off. All of that happens in about 1 second. That day I switched the machine on about three times and within a few minutes it performed the same behaviour. On the fourth switch on the blue was gone, so there was a picture with a large amount of yellow and green. The TV stayed like this for 2 to 3 days. I thought the tube was faulty. When I switched the TV on yesterday there was a large amount of blue tint. I used the service mode to re-arrange the green, red and blue values to get the best picture. Before all this happened I was about to sell the TV. Please could anyone provide any suggestions?