Ok well I have a

Ok well I have a 61inch rca projection tv and I thought the red tube went out. Well I bought a tube and installed it and the red screen was about two inches to the right I tried everything that I can think of I even reinstalled the old one just to see if the blue and green were still perfect and when I turned it on the red tube was working but I still had the same problem I cant seem to get the red screen to slide back over where it is supposed to be.I was wondering if there is a different problem or if I forgot to do something.