Replacing LDs in a M-140 with LEDs?

[ekeup]

With all the M-140 projectors having their LDs removed, I was wondering if those LDs could be replaced with LEDs instead to get it back working?

I'd like to replace my current projector ($200 cheapo) with something nicer, and would think this would be a nice project. I know it wouldn't be nearly as bright, but I don't really care about that (only watch at night in the bedroom).

Any ideas?

 

[Bionic-Badger]

Even if you could get it to work, you're looking at orders of magnitude less brightness because those 24 or so blues are used for both green and blue in the projector. The white point would be VERY red. Those blues are also each powered with 1 amp or so of current, which few LEDs will handle, especially in such a small area that they'd need to fit. You might be better off spending the money on some cheap-ass pico projector.

 

[ekeup]

Even if you could get it to work, you're looking at orders of magnitude less brightness because those 24 or so blues are used for both green and blue in the projector. The white point would be VERY red. Those blues are also each powered with 1 amp or so of current, which few LEDs will handle, especially in such a small area that they'd need to fit. You might be better off spending the money on some cheap-ass pico projector.

I assume there's some sort of color balance that could at least partially correct the color. As to the brightness... I would actually LIKE orders of magnitude less brightness... my current projector is 50 lumens and it's actually plenty bright for the environment I use it in. I'm just looking for higher resolution, not more brightness.

Does the projector work without the lamp module? could it just be completely replaced with a bright 'white' light?

 

[Bionic-Badger]

I'm talking about severe color balance issues because two of the channels are effectively killed off. You're looking at 24W of chromatically pure blue light that fluoresces to create green light in that projector. In normal use, the projector balanced that out by about 30W of red from the red LED and even then it is somewhat off. I don't think you'd have enough dynamic range to color balance it correctly. Getting the projector to think it is still powering those LEDs is a pain too. Someone tried tricking the M140 into working without that array of lasers with a big fat resistor submerged in water I think. It was literally boiling.

You might be able see if you can trick the projector into detecting a lamp being present and then use a white LED or something instead. I'm not sure if they use just a switch-based detection system, or if they detect if there is a load for the power supply.

 

[ekeup]

Did more research... and found a LOT more has been done on this already:

Running the XJ-A140 With Missing Diodes