Just wanted to thank Toms Guide and this forum. Had the white spots appear on my 73 Model WD-73C10" this past Friday. Found this forum, called Mitsubishi on Tuesday, and today Friday tv has been repaired. Mitsubishi forwarded part to tv repair shop, service showed up when part was received. As stated in forum, Mitsubishi "good willed" the cost of part, but the tv shop charged $200 for service (as set up by Mitsubishi ) After watching the repair work, it can be done with not much effort, just alot of screws to remove.
Live and learn.....I'm happy, and thanks again so much for your help here !!! Mitsubishi #1-800-332-2119