I went to use my projector the other day, and found that I was getting a blinking blue power light. The lamp light would also blink orange, one time, for a split second, and then go off. The online manual says *nothing* about this being a symptom of *anything*. I did some digging around online and discovered that the cause may be a bulging capacitor on the power supply board.
I removed the lamp (which appeared fine) and then all the screws on the bottom. In order to remove the top of the chassis, you must remove the two VGA - A screws on the back, near the port.
After many screws, cussing, and prying, I was finally able to work my way down to the power supply board, where there is indeed a bulging capacitor. Since this projector is two years old, out of warranty, and the warranty cannot be extended, I've no choice but to remove the capacitor and replace it with another 3300uF 16V.
If you receive a blue blinking power light on your Dell 1800MP projector (a $700 purchase) do NOT throw it out. This issue can be fixed by messing with a few dozen screws, a $.39 capacitor, and a soldering gun. Find a fellow to solder it on for you, and your projector will be working like new.
This image features a picture of what the bulging capacitor looks like: http://img.photobucket.com/albums/v350/Soul_Erosion/Picture013-1.jpg