Monitor problems

Well I had a 19 inch CRT that I got from the Thrift Store they said it was broke and so I took it home to check it out. Well it was fine so I brought it to college about a week later I figured out what was wrong. Once in a blue moon it would turn everything a lovely tint of pee-yellow. All ya had to do was hit a little and it would go back to white. Well that day is no longer. It has been stuck that yellow for over a week. I went home and switched out an old at home from my parents flat panel which is now at central, with me. Those 19 inch viewsonics take up a lot of room.