Facing TV Problems? Ask a TV Technician.
I wish I had better news for you, but what you have is a defective light engine (or optical block, as Sony calls it). This is a known problem with this series of Sony TV's. Sony used to cover this part under warranty even if your original factory warranty ran out. They stopped doing this, and instead were offering customers new flat panel LCD TV's as replacements (although they were offering only their cheapest bottom of the line units, but new nevertheless).
I think they have since stopped this offer, and you may be on your own. But I would definitely try contacting a Sony authorized service provider and see what they say. If it's not going to be covered, this will be an expensive repair to have a new Sony light engine installed. But there are rebuilt light engines available, and that is worth looking into.
If you'd like more info on this, take a look at All About Sony's Optical Block Issues.
Let me know if you would like more info on this, and thanks for using JustAnswer!