I stated in a previous post that any flat panel TV which lasts anywhere near ten years will be one for the books. Several hours after I made that statement, I realized that someone here on VK has such a set, a "Coby" branded 15" FP HDTV that is now well over a decade old and still works. I don't remember offhand who said that.
I believe that the smaller an HDTV is, the longer it will last, simply because of the lower power requirements of smaller sets; also, if a FP TV is not used much, it will likely last somewhat longer than one that is on eight hours or more a day. The LCD panels on most flat panel sets are rated for 60,000 hours to half brightness, which equates to over 20 years of use; however, this does not necessarily mean the set will last that long. VK member timmy, in New York City, stated in one of his posts a few months ago that flat screens generally last between two and five years before they develop service problems, such as bulging or burst electrolytic power supply capacitors. If one knows where to look on the power supply board, replacing the defective capacitor could be very simple, involving just cutting out the bad part and soldering the new one to the leads still on the board. This, of course, only works for boards that do not have surface-mounted components; even if it is possible to remove the defective part, replacing it could be a real problem on boards having mostly or completely surface-mounted components. This is probably also why many service centers today will simply replace a defective TV with a new one, so the customer won't have to wait days, weeks, months . . . for the set to be repaired. The old set will be repaired at the factory and likely resold as a used TV.