No power after replacing bulb

The solution from bjwjb posted on Dec 30, 2009 is absolutely correct:"There is a piece on the bulb cover panel that you take off in order to change the bulb that fits down inside the bulb assembly when you put the panel back on. The bulb cover panel and the part of the panel that goes down into the bulb assembly must be present or the projector will not power up (there will be no lights either)." I would add to that once the cover is placed back, but before the screws of the bulb cover are tightened, firm pressure should be place on on the bulb cover panel on the spot placed where the plastic protrusion (a plastic "stick" about 1.5 inches long that fits into a void in the bulb assembly) goes into the bulb assembly. You should/may hear a "click", indicating that the protruding plastic piece has been fully inserted into the bulb assembly and makes contact with whatever contraption is inside the assembly to enable power-up. If no pressure is exerted the plastic protusion may not extend down far enough to make contact to enable power-up. In such case the bulb cover panel may be slightly bulging in the location of the protrusion. You would still be able to tighten the bulb cover panel screws, because the plastic is flexible. In such case you may find that the screw closest to the location of the plastic protrusion may need pushed in more. In this condition, even though you may think the cover is properly placed, the plastic protrusion is not fully inserted and does not make contact and there are no lights or power. Just take of the bulb cover panel place it back following the instructions above.

I had already disassembled my projector and was ready to bring it in for service when I did an internet search and saw the advice from bjwjb. Thanks very much!

Thanks for the help. Worked great

BJWJB is right. In some cases however, no matter how hard the lids are pushed down, power will not run to the projector. We addressed this design flaw in a way that disrupts this feature.
Our solution was to put a small piece of electrical tape over the contact point, ensuring the tiny metalic gate would stay in the “on” (for lack of a better term) position.
WARNING-- POWER WILL RUN TO THE PROJECTOR EVEN IF THE LID IS OFF. THIS COULD PRESENT SOME DANGER WITH THE FAN TURNING ON OR HARMFUL LIGHT SHINNING IN YOUR EYES.
Whatever, worked for us.

There is a piece on the bulb cover panel that you take off in order to change the bulb that fits down inside the bulb assembly when you put the panel back on. The bulb cover panel and the part of the panel that goes down into the bulb assembly must be present or the projector will not power up (there will be no lights either).

The lamp timer should reset as soon as you replace the lamp. if there are no leds lit on the top, then you have a power supply issue.