I have an 8 year old Sony projection/LCD. I replaced the bulb a couple years ago, otherwise has worked great. With projections, if the T.V. is moved often or in a rough manner, it is possible that one of the mirrors has adjusted, but the picture would be distorted all the time. Sounds like a reception issue, either a bad feed from your cable/dish or internally in your T.V. If internal, probably not worth fixing.
HH