Back in Decemeber I purchased a new Sony KP-57WS520. I discovered the TV had a problem: http://www.hometheaterforum.com/htfo...ighlight=waves I've now had three service techs out -- all have seen the problem. My last tech tried replacing the video circuitry board, however this did not solve the problem. He says the only other option would be to replace the power supply board. However, the Sony engineer he had to call would not let him order the part until the wave pattern has been verified on a singal generator (even though the waves appear on every input on the TV even when know image is displayed). My tech came out with the generator in the afternoon, however, the waves weren't to be seen because the room was too bright (the room is darker in the morning, but he couldn't come out in the morning). This wave pattern can really only be seen in a dark room (such at night) in dark scenes of movies. The Sony "engineer" also told my tech to tell me I should have my contrast boosted to 66% while keeping my brightness at 50%. On any rate, the Sony service person is now trying to just get me to get a 4th tech out --- for some reason they don't want this current tech doing anymore work since he has already worked on my set with no "cure." However, they offer NO advice to him or any of the other service techs I've had out. In all honesty, I feel I am just getting no where with Sony. All of their so-called engineers appear absolutely useless at best --- and offering advice which can destroy my display if I didn't know any better. I just can't believe the only advice is to boost my contrast to 2/3. Any suggestions? Should I just go to the Better Business Bureau? Would this be a waste of time? All I can say is I will NEVER buy another Sony product again.