Here is a link to an interesting website. It relates to the Blue LCD burn problems that I and others have referenced. If you want to take the time to read it you can see some of the resulting images after various types of failures. It also references the organic and UV issues that have been brought up in this threadhttp://sites.google.com/site/sonylcdrptvproblems/
For those of you who don't want to read the entire thing below is a C/P of some of the relevant parts:
The television image is created by projecting light from a high-intensity mercury vapor arc lamp onto three small (approximately 1" across) liquid crystal panels inside the optical block. There is one panel each for the colors red, green, and blue, and they are combined with a prism and enlarged onto the back of the large viewing screen with a projection lens. Depending on the TV model, the optical block is based on one of two liquid crystal technologies: conventional liquid crystal display (LCD) technology ("3LCD" models) or liquid crystal on silicon (LCoS) technology ("SXRDTM" models). All of the 2002-2006 and some of the 2007 models use the WEGATM video processing engine and are generally known as Grand WEGAs. The remaining 2007 models use the newer BRAVIATM engine and branding.
The discolorations arise due to degradation of parts within the optical block assembly during long-term exposure to heat, light, and/or dust. The high-intensity lamp is attached to the optical block, and it creates a lot of heat. In addition, it creates intense light, much of which is converted to heat inside the optical block as it is filtered. Some of the light-filtering parts, including, in many cases, the liquid crystal panels themselves, utilize organic dyes or other substances that are subject to degradation from heat and light, particularly light in the high-energy blue light path (e.g., UV and deep blue). Also, the optical blocks are not sealed, so dust can accumulate on the internal parts, which can further reduce cooling efficiency, as well as directly cause discolorations.