I am looking for advice / experience / thoughts on my lamp bypass project. I am fully aware of the cons of alternative light sources, so please don't respond with that.

I did obtain the service guide for this projector and have a pin out of the connections between the ballast and the main board. So I thought it would be straight forward - short the "lamp lit" to the 3.3V bus. Doing this worked in that the color wheel keeps spinning. It does not however activate the DLP chip. If I re-connect the metal halide lamp, the projector puts out a fine image (even while the "lamp lit" pin is still shorted). My bulb is not quite dead and I've used a DMM to measure the 14 pins while the lamp is connected and not connected. There were no give aways...all voltages are the same (while "lamp lit" is shorted to 3.3V). The only difference I can measure with the DMM is the "lamp lit" normally sits at 3.0V as opposed to 3.3V. I'm thinking that there is some other signal when the ballast drops to 75VDC (lamp ignited) passed to the main board.

Thoughts? Feel free to message me and I'll pass along the service guide...

I tried bridging the opto-isolator (U5) on the out put side. Same result as bridging pin 3 ("lamp lit") to the 3..3V bus. Color wheel spins, but no image... I am so frustrated!