There are interlocks that will prevent the set from starting if the lamp is not installed correctly or if the access door is not closed properly. Either condition will result in a "lamp error" indication. Try reinstalling the lamp being careful to be suer that it is seated properly. Also make sure that the access door is fully closed and aligned. If you continue to get the lamp error, it is possible that the ballast circuit is defective. This is the part that generates the power to "fire" the lamp.

Keep us posted.
Dan