I am afraid I have no good news for you..
The problem you are describing is very common in your model, what has happened is the optical engine has failed and needs to be replaced. This is bad news because to have one replaced will run over $1000 in most cases. Sony had a major problem with these over time and actually had a extended warranty on them, where Sony was replacing them free of charge. However most of these warranties have now expired and they are no longer repairing these problems at their cost. You need to contact a local authorized servicer in your area and give them your model and serial number, they will be able to determine if your set is still covered under the warranty. If it is then they will be able to repair it at no charge to you.
If your set is not found to be under the warranty then the only good advice I can give you is to call sony customer service and complain to them, allot of the times they will still repair this set for you at no cost or offer you a new set at a "discounted" price.
Again I am sorry I don't have a quick fix or easy answer for you on this one, but the optical block will need to be replaced. Hopefully you are under warranty but if not calling Sony and complaining is your best course of action at this point.
If you would like any additional information or have more questions please don't hesitate to ask!
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