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Thread: Getting a projector to work without LD's

  1. #1
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    Default Getting a projector to work without LD's

    Well, I have a few empty projectors now, and I've been experimenting to see what I can find, and if there is any way I can get them to power up without any LED's, and wihtout having to use bulky, hot resistors.

    I have found the LED and LD's are both controlled from 1 PCB. This PCB gets power right from the PSU, and only has 1 ribbon cable between it and the main PCB. So, the error signals must be travelling through this ribbon cable, so my aim is to try and find it, and trick it into thinking its OK. I have taken some closeup pics. Casio were nice enough to label pretty much ALL the connectors, and even supply a plethora of diagnostic pins, so maybe someone can help interpret anything that could be of help!





    We know the projector shuts off with both overtemp and missing diode warnings. So there has to be at least 2 error lines here. Worst case it uses serial communications for error reportings.

    Cheers,
    Dan
    Last edited by Things; 12-14-2010 at 06:24.

  2. #2
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    I assume you have seen my thread at http://www.photonlexicon.com/forums/...Missing-Diodes which details my findings, and has some fairly detailed notes on the projector operation. There are also x-rays of the motherboard and diode driver board for tracing the buries traces.

    There are actually 2 serial communication lines, I haven't had time to wire in a logic analyzer to them, but I believe one of them is SPI and the other is I2C. I haven't added my latest round of notes into my post, but I have mapped out most of the analog inputs to the R5F212CASNFP processor, and have had mixed luck defeating the voltage compliance. I first tried just shorting 3 of the channels, and connecting the voltage sense pins of those 3 channels to that of the remaining working channel--but this put too much stress on the shorted channels and blew out the mosfets. I have started work on doing the same for the current compliance pins, but currently am in the middle of our house being sold so progress has been slow.

    So far my general impression is that the ideal solution would be to spend the time with a logic analyzer and decode the serial interfaces so that you could spoof the diode driver board completely, this would also give the added benefit of being able to use the diode driver board as a standalone unit for driving high power lasers. The downside to this method is that depending on how the circuitry is done, you may loose the ability to get the red led/tec driver working without the blue diodes, so it would not work for a red-only mod.

    One brief glimmer of hope is that there is a serial LED driver interface talked about in the DLPC200 manual (note-the actual chip in the A130 series is a DDP2431, which I cannot find on TI's website) which looks like it might be one of the busses on the display board--in this case it should save time in the reverse engineering department.

  3. #3
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    I also had a glimmer of hope last night. I disconnected the ribbon cable completely, and the only error the projector gave was that the light sources hadn't turned on. Althought it makes me wonder if everything is done through serial communications.
    Last edited by Things; 12-14-2010 at 17:16.

  4. #4
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    I am curious, what do you mean by 'the only error was that the light sources hadn't turned on'

    In my testing, with a missing driver board the projector wouldn't make it past the 'spin up color wheel and apply power to the DMD' stage, and after a few cycles of spinning up the color wheel it would give 3 red flashing lights. IIRC I got a flashing green power LED, not to be confused with the flashing green lamp LED (which is not a problem, and simply means the projector is in echo mode).

  5. #5
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    According to the manual the 3 flashing red LED's means that the light sources did not turn on. This is expected because the main board can't tell them to turn on, though.

  6. #6
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    OK well, I've had some nice success! Not intercepting signals, but I have managed to achieve a passable white with only 5 (Yes, FIVE!) diodes. And of course, some high powered resistors in a container of water

    Basically, I turned the red right down and green and blue right up on the projector, and also did the same on my graphics card.

    Before:




    After:








    And if this isn't the craziest thing you've seen all day:






    Not ideal, but proof of concept.

    Cheers,
    Dan
    Last edited by Things; 12-17-2010 at 04:50.

  7. #7
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    i know im resurecting a possiably a dead thread but i was wondering if you had anymore luck Things/dan..if so id be very interested in your findings as well.

  8. #8
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    is there really a need to go through every 445 thread and comment, no matter how old the thread is?
    Eat Sleep Lase Repeat


    Aluminium Optic Mounts

    http://www.laser-man.co.uk/opticmounts/

  9. #9
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    Quote Originally Posted by andy_con View Post
    is there really a need to go through every 445 thread and comment, no matter how old the thread is?
    i was thinking i was the only one getting annoyed by this.
    Its not even about the lasers, but he is only interested in getting a stipped out projector to work without the lasers.

  10. #10
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    just looking for data and information about peoples experiments thats all...if your going to make a thread on the internet you have to accept that people are going to answer it even if its dead or not..and yes my goal is to get a projector without the lasers to work.unless its costing you something,or taking food from you or yours mouths,i dont see a reason to complain.


    im not asking for one of your kidneys or to date your daughter,just some information is all.
    Last edited by kobra000; 10-23-2011 at 16:03.

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