I searched high and low for instructions on how to replace the lamp on a Proxima DP6850+ projector. Couldn't find any anywhere and I didn't want to take ours down from the ceiling if I didn't need to. With no instructions available I decided the only way was to take it down. Here's the replacement procedure.
The lamp door on this model is on the bottom (the top of it's ceiling mounted with the controls facing the floor). So I would have needed to take it down one way or another.
There's a single door and a single screw holding the door. Go ahead and loosen the screw and tilt the door back to reveal the lamp inside.
You will find two screws at the front of the lamp holding it in place. Loosen these two screws. There's a handle on the top of the lamp. Use a fingernail or screwdriver to gently pop the handle up and pull the lamp straight up.
Before you place the new lamp in, inspect the face of the lamp to make sure there's no packing material or contamination on it. Use a clean, lint free cloth to remove any particles.
Take the new lamp and slide it straight down into the housing. Make sure you seat it fully. There are two plastic tabs next to the screws at the front of the lamp. Verify that they are in place and that you have pushed the lamp down far enough. Similarly, made sure the back left of the lamp is pushed down far enough to seat the power connector. Tighten the screws at the front of the lamp.
Put the door back in place and tighten its screw.
Now that you have the projector down it's a good idea to make sure the filter is clean. This is located at the front of the projector and is held in by a plastic tab.
There are three parts to the filter assembly: the frame, a filter, and a square fitting to hold the filter in place.
Gently snap the square fitting out to remove the filter. I prefer to wash the filters myself. Shake or blow out the majority of the dust out with compressed air then run it under running water from back to front to clean it. Make sure it is completely dry before reassembly. I usually roll the filter in a towel and squeeze it dry.
Reassemble the filter aligning the shape of the filter with the shape of the outer frame. Gently snap the square fitting under the tabs of the frame. If the fitting's edges are bowed in you probably don't have it seated far enough.
When you're done, make sure you reset the hour timer for the lamp. Turn on the projector and make sure there's an active video source or you won't be able to access the on-screen menu.
Press and hold the reset button on the projector's keypad for 3 seconds. You'll see the lamp hours at the bottom of the screen. Use the arrow buttons to select "0" then press the reset button again for 3 seconds. This should set the timer back to 0.