Sony 50' LCD Projection KDS50A2000 has a green tint on the screen

Hello. Sorry for bringing bad news but your optics block is getting bad. It is very common issue with Sony LCD projection TV and even recall was issued. You can call Sony Customer Service to figure out if your model still covered by Sony warranty. It is very expensive repair, major optical assembly in your TV have to be replaced and total cost is not less than $600.
If you not covered by warranty anymore - there are not many options but to look for new TV.
Green tint on your screen will get progressively worse.
There is nothing you can do by yourself, unfortunately.
Good luck!
Russ.

Sony TVs has an Optical Block issue. If there is an issue with the optical block, then there will be green, blue patches or tint on the TV display. Try resetting the TV to the factory settings and try Power resetting the TV. Turn Off the TV and remove the power plug from the wall outlet for 1 minute and reconnect it and check the operation. If the issue still persists, then TV may require service. You can contact the Customer relations team and check for the available options. Sony had repaired free of cost for such issues. Hence, contact the customer relations.

OPTICAL BLOCK IS GONE, 1000.00 TO FIX IT. SORRY, YOU MISSED THE RECALL DATE...JUNE 2009

I tried this solution last night. had a similar issue. opened up the back panel and cleaned the fan. just for the fun of it, i tried to turn the tv on and presto. it works fine now and i probably saved a bundle. thanks!!!

You have a bad light engine call Sony and see if it is on their extended warranty list

This may be due to Optical block. Click the link below to review Certain 2006 Model Year SXRD Television Extended Warranty Information - Optical Block

http://esupport.sony.com/US/perl/news-item.pl?news_id=277&mdl=KDS50A2000

bad optical block call sony they have a recall

sounds like you need a new light engine. Sony can probably get you one at no cost if make enough noise, they are aware of problems with their light engines. good luck

My Sony KDS 50 A2000 is 17 months old. Its the 50 Inch SXRD projection model. About two weeks ago the screen developed a green tint with cannot be tuned out, then a few days later the message began to appear on the screen that the bulb was nearing the end of its life and must be replaced.
Fortunately I have the Circuit City extended warranty.
I called and within just a few days a serviceman came out and replaced the projection bulb.
The Result: No change in the picture, the green tint remains on all channels, so I'm awating the next service call. Under the service warranty they have the option to repair or replace this set. If indeed this is the light engine (optical block) which I suspect and its going to cost $1,000 or more I may be looking at a new set.
When it works this is a great TV, but I have had three Sonys now including two other standard CRT models and now this one joins them in the junk heap, the other two also bit the dust after just about two years. Is it time to give up on Sony?
I know they have a class action suit on a similar model for this same problem. Caveat emptor

They are one in the same IIRC. I'm having my TV repair for the same issue. Don't worry for now because the item has had its warranty extended to Oct 08.