Thank you for the information. The first thing to check is the lamp, especially if it has not been replaced in some time. If you were to remove the lamp and look inside the glass at the globe inside, if the globe is "blistered" or discolored, then a lamp will likely solve the problem.
If the lamp is okay, you will very likely have a defective light engine. The LCD
panels in the engine are exposed, so they tend to collect with dust and block the light path. It is not recommended to try to clean these because the dust can enter other parts of the light engine.
This is an extremely expensive part: over $1000 plus shipping, tax, and labor. I recommend contacting Mitsubishi Customer Relations at (800)332-2119 and insisting (very insistent!) this part be replaced at no cost. The dust problem is common, so they should at least provide the part at no charge. The customer is usually expected to pay the labor, in the range of $200-300 in my area, depending on the trip charge. However, it will not hurt to ask for the labor also.
Important: Usually Mitsubishi requires one of their authorized servicers to check the TV first, before they will offer a concession. It is best to have an estimate of the repair from the technician before you call Mitsubishi.
I hope this information will be helpful when you call, and if I can help in any way, please let me know.
Edited by Steve on 10/3/2009 at 3:05 AM EST