GLAMPS VLT-HC3800LP Original Lamp with Housing for Mitsubishi Hc3200 Hc3800 Hc3900 Hc4000 Projectors For MITSUBISHI HC3200 HC3800 HC3900 HC4000 New replacement Projector Lamp with original bulb and compatible Housing VLT-HC3800LP Projectors operate at very high temperatures and many fail-safes have been implemented to it. The most common being the one that prevents the projector to start unless the lamp door is sealed properly. Please make sure that the back door is closed and screwed tightly. In many cases is also crucial to perform a lamp timer reset after installing a new projector lamp in order for the new lamp to become active. Many projectors will turn off automatically when the end of lamp hours has been reached  whether the lamp is new or not. That is why its very important to reset the lamp timer. Projectors will also turn themselves off automatically if they detect any problems and one of them is when the air filters or ventilation holes are clogged with dust or other debris. This overheats the device and wont let all its component to perform at their fullest. Use a can of compressed air to keep your filters and ventilation holes dust free. NOTE: Projector lamps CANNOT be tested with an AMP or OHM meter. Projector bulbs function by igniting ultra-high pressurize mercury vapor contained inside an ARC tube. There is no conductive electrical material contained in the ARC tube besides the gas.