• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 1 answer
  • Subscribers 28 subscribers
  • Views 904 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DLP5500 micromirrors don't switch

Fang Xu
Prodigy 80 points
Other Parts Discussed in Thread: DLP5500, DLPC200

Hi,

We're using the DLP5500 DMD for academic research. But plenty of micromirrors in our DLP5500 DMD doesn't work. In videos projected by the DMD, some pixels are always bright or always dark. Could you help me figure out the problem?

Our DLP5500 DMD is a part of LogicPD's DLP LightCommander Kit which is discontinued.  If it's a hardware problem, is it possible to replace it with a new DLP5500 and fix this problem?

Below is a "black" image the LightCommader projected:


And below is how it looks when projecting a white image:


When the white image or the black image is projected by the DMD, some "pixels" are always black or white.

I've upgraded the firmware of DLPC200 (MCU 2.2.0) but it didn't help.

Any help would be appreciated.

Thanks,
Fang

  • 0
    TI__Guru 54320 points

    Hello Fang,

    Welcome to the DLP section of the TI-E2E Community.

    When you turn the unit on, do you briefly see the LED's flash?

    The other thing to check is to see if the DMD is completely seated in the ZIF socket.  If it is, then you need to remove the controller board and then the DMD board so you can turn the ZIF socket cam screw to release the DMD.  Then try reaseating the DMD and retightening the ZIF cam screw. 

    Reassemble and see if it will now display images.  If it shows images with some vertical stripes (and/or one or more black horizontal bands), then one or more of the pin receptacles in the ZIF socket may be damaged.  You will need to obtain a new ZIF socket and replace it on the DMD board.

    Fizix

  • 0 in reply to Fizix
    Prodigy 80 points

    Hi Fizix,


    Thanks a lot.

    I've tried to reseat the DMD and retighten the ZIF cam screw following your advice. But after reassembling, the same problem remains. Some certain pixels (distributed randomly) are always bright or dark as in the images of my original post.

    Every time when I turn the light commander on, the LEDs keep flashing. But I just encounter the problem recently.

    Do you think there are other causes?

    Best,

    Fang

  • 0 in reply to Fizix
    Prodigy 80 points

    And there's another symptom. When display static images, a few certain pixels keep flipping over and over, which is also abnormal.

  • 0 in reply to Fang Xu
    TI__Guru 54320 points

    Hello Fang,

    This is not expected behaviour.  To make sure that I understand correctly let me ask the following:

    1. Did the unit ever work correctly? 
    2. Did the "bad" pixels build up slowly over time or happen all at once?
    3. For the static images with pixels that keep flipping, are they 1 bit (binary), 8 -bit (grayscale), or 24 bit (RGB-8,8,8 color) patterns?
    4. Are you using the original LED engine or another light source/engine?  If yes:
    • What wavelength(s) and optical power density at the DMD?
    • What type? (i.e. Lamp, LED, Laser - pulsed or CW)
    • What are the environmental conditions that the unit is operated in?  (i.e ambient temperature, relative humidity, etc.)

    Fizix

  • 0 in reply to Fizix
    Prodigy 80 points

    Hi Fizix,

    Thank you very much for your patience.

    1. Yes. It had worked correctly for several months.

    2. I'm not sure about this. I used the DLP as the light source of a microscope system. I just found the problem recently. But it must have existed for several weeks. I think it's more likely that most "bad" pixels get bad all at once.

    3. The static images are 1-bit.

    4. Yes. I'm using the original LED engine in the DLP LightCommander.

    • I usually use all blue, green and red light at 20% power. Occasionally I used 60~100% blue light for several seconds.
    • We use air-conditioning so the temperature is around 20 C and it's not humid.

    I uploaded a video to Dropbox revealing the problem. I projected an white image (1-bit) to the wall at the beginning, and at ~00:05, a black image (1-bit) was projected, and at 00:17, the white image was projected again. Only a part of the full projection image was captured.

    https://www.dropbox.com/sh/aeh2zof3zlguo3o/AAADGEjps5oMS9gB3CvMk63Ra/DLP_problem.MOV

    You'll see:

    (1) There are many "bad" pixels when displaying white or black images.

    (2) When white images were projected, one pixel in the middle kept flipping (before 05:00 or after 00:17).

    (3) When the projected images altered from white to black or from black to white, the transition of many pixels lagged.

    And I just remember another abnormal thing... I found the compiling time of the LightCommander after I pressed the "Run" button is much longer (~2 s) than before when it worked correctly. I also uploaded the run-log to Dropbox:

    https://www.dropbox.com/sh/aeh2zof3zlguo3o/AAAdgaK6wEN2gZSzq1OhwTe1a/runLog.txt

    I'm grateful for your help.

    Fang

  • 0 in reply to Fang Xu
    TI__Guru 54320 points

    Hello Fang,

    Could you try loading one of the demo projects.  Specifically the LogicPD logo.  Please see if it runs correctly or exhibits the same issue.

    Thanks.

    Fizix

  • 0 in reply to Fizix
    Prodigy 80 points

    Hi Fizix,


    Thanks for your reply. But I found I can't run the demo project LogicLogo.lcp.  I've tried to reinstalled the LightCommander s/w in two computers, and tested the f/w version 2.1.6 and 2.2.0, but every time when I tried to compile and run the demo project, the s/w crashed.

    It looks like the demo project cannot be correctly compiled.


    Best,

    Fang