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Thread: Analyse This!

  1. #1
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    Default Analyse This!

    Ok, need some suggestions as to what MIGHT be wrong here. Not much info to go on, but see what you make of it.

    I have a laser projector, RGB. It will run under DMX control. I can only get 4 colours out of it rather than 7 though: blue, cyan, magenta and white. If any of the diodes are on, the blue is on. This behaviour manifests in the laser's demo mode, too. What might cause this?

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    Quote Originally Posted by smokeAndMirrors View Post
    Ok, need some suggestions as to what MIGHT be wrong here. Not much info to go on, but see what you make of it.

    I have a laser projector, RGB. It will run under DMX control. I can only get 4 colours out of it rather than 7 though: blue, cyan, magenta and white. If any of the diodes are on, the blue is on. This behaviour manifests in the laser's demo mode, too. What might cause this?
    Hi there,

    Are you able to isolate the colour signals to the driver(s) or the current to the lasers? It seems that the signal or the current for the blue is permanently on, most likely because of a short.

  3. #3
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    Quote Originally Posted by taggalucci View Post
    Hi there,

    Are you able to isolate the colour signals to the driver(s) or the current to the lasers? It seems that the signal or the current for the blue is permanently on, most likely because of a short.
    Can't do anything hardware-wise because the laser is new, I'm hassling the manufacturer (in China - yes I know, I know), and I don't want to void warranties. But this remote diagnosis will help me in my dialogue with them (hopefully).

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    Sounds like a green problem to me although I have very little practical experience and defer to Tagalucci on this ie. try his suggestion 1st!!!.

    From here: http://en.wikipedia.org/wiki/Magenta

    magenta can be produced by removing the lime-green wavelengths from white light. It is an extra-spectral color, meaning it cannot be generated by a single wavelength of light, being a mixture of red and blue wavelengths.
    So it appears all of your colours are either red or blue mixes with the exception of white. I wonder therefore if you have some green but very little.

    Have you tried outputting green alone and taking a power measurement?

  5. #5
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    Quote Originally Posted by White-Light View Post
    Sounds like a green problem to me although I have very little practical experience and defer to Tagalucci on this ie. try his suggestion 1st!!!.

    From here: http://en.wikipedia.org/wiki/Magenta



    So it appears all of your colours are either red or blue mixes with the exception of white. I wonder therefore if you have some green but very little.

    Have you tried outputting green alone and taking a power measurement?
    Hmm, could hook up my FB3 to do that. I have a laserbee somewhere...

    (However since the cyan is strong and the white is crisp, I am still largely convinced that it is the blue is the problem.)

  6. #6
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    Quote Originally Posted by smokeAndMirrors View Post
    Ok, need some suggestions as to what MIGHT be wrong here. Not much info to go on, but see what you make of it.

    I have a laser projector, RGB. It will run under DMX control. I can only get 4 colours out of it rather than 7 though: blue, cyan, magenta and white. If any of the diodes are on, the blue is on. This behaviour manifests in the laser's demo mode, too. What might cause this?
    I think your problem has more to do with the internal DMX board than anything else.

    The dreaded LaserWorld projectors have this kind of problem.
    On the DMX board inside the projector you will find (probably!) some dip switches which give a combination of different colours without rhyme or reason.

    Try putting +5vdc on to the colour input pins of your ILDA input and bridging the ILDA (projector connected pins). This should give white beam with no scan. Then remove each colour one by one. If all work properly then diagnosis is pretty firm.

    Despite DMX hangups the projector will probably work OK with ILDA input.

    Cheers

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    Quote Originally Posted by smokeAndMirrors View Post
    Hmm, could hook up my FB3 to do that. I have a laserbee somewhere...

    (However since the cyan is strong and the white is crisp, I am still largely convinced that it is the blue is the problem.)
    If the green was still working a little you could get cyan.

    The thing that makes me suspect green is the fact that you can't get yellow which is red + green. We already know you can get all of the blue colours which confirms that the blue is working. Magenta seems to confirm the red is working so that and the absence of yellow seems to suggest a weak green to me OR maybe its more likely a laser driver / controller issue as Catalano says, as I've just noticed you haven't reported seeing red on its own either.

  8. #8
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    A quick test with my FB3 showed that the projector works just fine. So the culprit is the integrated controller board (not just DMX, but the demo/sound-to-light functions). What is the reckoning on a likelihood of repair?

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    What I'd be inclined to do 1st is video the problem, then email them and say that you've narrowed it down to a problem with the DMX board. Here's a link to a video of the problem confirming its the DMX board, can you please send me a new one as I'm more than capable of fitting it and it will save postal costs on me sending and you returning the projector?

    I'm assuming you're more than capable of switching the boards out.

    Hopefully they might agree as its the cheapest and easiest option for them as a small dmx board weighs next to nothing in the post.

    The reason why I'd do it this way is because:

    1. Its quicker and cheaper for them

    2. Its safer for you - you don't end up sending your entire projector half way around the world only to have it:

    • Not returned
    • returned but damaged in another way
    • lost or damaged in the post

    Of course the downside is if you do this, you're admitting you've opened it so they could technically declare the warranty void and refuse to help you.

  10. #10
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    Quote Originally Posted by White-Light View Post
    What I'd be inclined to do 1st is video the problem, then email them and say that you've narrowed it down to a problem with the DMX board. Here's a link to a video of the problem confirming its the DMX board, can you please send me a new one as I'm more than capable of fitting it and it will save postal costs on me sending and you returning the projector?
    LOL, tried this. Because the manufacturer is in China, they are unable to view anything on Youtube (banned by their glorious government). They may be able to see other sites, but (see next paragraph).

    They have said I can have refund if I send the laser back - they refused to replace or repair. Sadly I need it for a show on Saturday but they've been less than cooperative. In fact because I gave them bad feedback on eBay and escalated my complaint, they are now refusing to have further dealing with me

    Quote Originally Posted by White-Light View Post
    I'm assuming you're more than capable of switching the boards out.
    Me - I'm a software dude. Hardware is like... not metaphysical enough. However, I know someone who can :-)

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