Well, my 640, which I have had a year, developed these white spots on the screen on light or gray scenes, lower left quadrant. Costco turned me over to Sharp and after sending images of the screen, they are sending out a refurbished set. It will be reinstalled on the wall and all packing hauled away. They were very helpful. A bit concerned about the refurbished set, but they said if I am unhappy with it on arrival they will take it back. Hope this all works out. Costco covers the first 90 days, you can return it for almost any reason. After 90 days the manufacturers, Sharp, coverage begins and lasts for one year after the Costco 90 days. After the one year of Sharps warranty Costco cover the remaining period up to two years. I bought Square Trade for $59.00 for another 3 yrs after that. If there is any problem with the refurbished set after Sharps warranty ends, about 80 days, Costco will cover any problem and fix or replace the set. I hope that won't be necessary
