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DLPC7540: Display doesn't work as expected

Jonathan Navor
Genius 9155 points
Part Number: DLPC7540
Other Parts Discussed in Thread: DLP471TE, , DLP471TEEVM

Tool/software:

Hi Experts,

Good day!

Posting this on behalf of the customer.

We are using a DLPC7540 with a DLP471TE as an SLM in an optical system. These days, we found the display doesn't work as expected. There is no display while it is connected to the external video source. We also test the test patterns, it displayed some random pattern I attached below. We tried to check all the connections and also flash it with the firmware again, it doesn't help.

Do you have any suggestions for this issue?

Best regards,

Jonathan

  • 0
    TI__Mastermind 45415 points

    Hello Jonathan,

    Our DLPC7540 expert is out until Monday (6/24).  I have assigned this thread, but there will be a little bit of delay

    Fizix

  • 0 in reply to Fizix
    TI__Genius 9155 points

    Hi Team,

    A gentle reminder for this request. 

    Regards,

    Jonathan

  • 0 in reply to Jonathan Navor
    TI__Genius 9155 points

    Hi Team,

    Our customer made some progress but still encounters errors. Here is the update below: 

    We followed the firmware reset process as described in the DLP7540 user guide (sections 2.3-2.4), wherein the jumper on pin J67 is transferred to J9, a fresh firmware is flashed (the firmware was downloaded from the TI website and is meant for the DLP7540 in conjunction with a DLP471TE), and then the jumper is returned to J67. Of course, the system is powered off while transferring the jumper. After performing the firmware update, the display does not show the TI DLP splash image, and is instead blank. If we use the DLP EVM GUI to configure the system to display a test pattern, nothing is output (although a faint vertical line appears). If it is configured to output Splash Image #1, we get the same random pattern Xi mentioned in her original message. For reference, all the appropriate LEDs are on (D5, D6, and D7 are constantly on, and D15 is blinking roughly 3-4 times per second).
    Regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Expert 3820 points

    Hi Jonathan,

    Please allow us a couple more days to get back to your update. I am unsure if our colleague is back in the office just yet or if he is catching up on emails, but may I ask if the customer has their flex cables correctly oriented, aligned, and fully connected? Are the connectors clean and free of any possible debris?

    This is just a thought to get past any "aha!" moments regarding the DMD. Thanks for being patient!

    Regards,
    Michael Ly

  • 0 in reply to Michael Ly
    TI__Genius 9155 points

    Hi Michael,

    I understand. I'll be waiting for your update. Thank you.

    Regards,

    Jonathan

  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    Sorry for getting back to you later than I had anticipated. I am assuming the customer is utilizing a schematic they made themselves as there is no reference to our EVMs.

    Thank you for including the images of what you were seeing! In the second photo I can tell that you are seeing a broken up DLP Logo. The typical logo should look like the below image, but the customers is broken up.

    Because we are seeing the jumbled image, I can assume the system just has the data pins in the wrong place for the DMD.

    Please have the customer check their HSSI Data connections from DLPC7540 to DLP471TE are connected properly. They should be able to check against our EVM schematics if there is any question under the DLPC7540EVM and DLP471TEEVM accordingly.

    Best,

    Aaron

  • 0 in reply to Aaron Black
    TI__Genius 9155 points

    Hi Aaron,

    Thank you for your assistance. I'll share this information with our customer. 

    Regards,

    Jonathan

  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    Of course, I'll await your reply.

    Best,

    Aaron

  • 0 in reply to Aaron Black
    TI__Genius 9155 points

    Hi Aaron,

    Please see the customer's feedback:
    We have verified that the flat flex cables are connected and oriented correctly. There doesn't appear to be any debris, but we used compressed air to ensure the connections are clean. We are still getting the same broken logo on the screen when attempting to show Splash #1, and a couple of random vertical lines when attempting to show any pattern from the test pattern generator. "External Display" doesn't provide an output either.
    Is there anything else that you can suggest? Thank you.
    Regards,.
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    The data lines themselves could still be mixed up through the traces. Again, if the customer has made their own system - I'm assuming they have because there is no mention of using one of our EVMs, either controller or DMD - then they are susceptible to having design flaws.

    The software we've published is meant to work with the hardware we've published, customers can modify this slightly but data output is meant to be sent to the DMD in the fashion we've published online.

    I'll suggest again that they look at the data bus connections from the controller to the DMD. Please provide me a copy of this schematic, I can take a look as well and will be comparing it to our DLPC7540EVM and DLP471TEEVM schematics which are available for public reference.

    Best,

    Aaron 

  • 0 in reply to Aaron Black
    TI__Genius 9155 points

    Hi Aaron,

    I appreciate your support and providing your insight on this. 

    Best regards,

    Jonathan

  • 0 in reply to Jonathan Navor
    TI__Genius 9155 points

    Hi Aaron,

    I clarified once more with the customer. 

    I apologize for the confusion. They are indeed using a DLP7540EVM to control the DLP471TEEVM.
    Best regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    Did this DMD just start to show this symptom? I will need more pictures for this then of the system. Please advise if the customer has tried to swap the connectors with new ones? The flex cables included in the EVM kits are meant to last for a while, but at times can deteriorate rather quickly.

    When we see vertical stripes, this is usually indicative of a signal integrity/input issue between the controller to the DMD and because both of the sides of the DMD are seeing artifacts I'm thinking they might want to try and re-seat the DMD as well - note that this is a delicate procedure and the customer should follow proper ESD regulations when doing so.

    Was anything pushed against the DMD horizontally or vertically? This DMD should be held within a LIF (Low-Insertion Force) socket and shouldn't have any pins with an issue - this is checked when initially built and assembled.

    Best,

    Aaron

  • 0 in reply to Aaron Black
    TI__Genius 9155 points

    Hi Aaron, 

    We'll be checking this with our customer. Thank you.

    Regards,

    Jonathan

  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    I'll be awaiting your response! Hopefully this can be easily fixed!

    Best,

    Aaron

  • 0 in reply to Aaron Black
    TI__Genius 9155 points

    Hi Aaron,

    Here is our cusotmer's latest feedbeck.

    I think it works well at the beginning, but it starts to have issues these days. Here I attached the figure about how we connect the DMD and the controller. We are still using the cables provided in the kit, we have three of them, two connect the controller to the DMD, and one connects the HDMI. We switch them around to test the test pattern, but it still doesn't work. We just leave the DMD as it was before, it is shown in the figure I attached.
    if it would be possible to return them for inspection. We would greatly appreciate your assistance in diagnosing any potential problems. 
    Additionally, we are considering purchasing a new device. Based on the issues we've encountered, do you think there might be a problem with the controller or the DMD?
    Thanks.
    Regards,
    Jonathan
  • 0 in reply to Jonathan Navor
    TI__Expert 6005 points

    Hello Jonathan,

    I can't tell if the controller or DMD has an issue just by the description of "it work[ed] well at the beginning, but it starts to have issues these days." I don't know what was done before it stopped working and after to try and fix the system.

    I would recommend first that the customer isolate the boards - take them out of their custom mechanical containers - and follow the steps for the quick-start guide within the DLPC7540EVM User's Guide making sure to follow steps for the DLP471TE software flash. Let us know what step this stops working, if any.

    If the board was working fine when received, this will be an operator error and can be guided by us but we shouldn't take the board back just to have this happen again. This isn't sustainable as many customers will have recurring issues like this. This is also why E2E is offered with historical threads and active interaction to work through possible issues.

    Best,

    Aaron

  • 0 in reply to Aaron Black
    TI__Expert 6005 points

    Hello Jonathan,

    We have not heard anything back for some time and will be closing this case.

    Feel free to respond or create a new thread accordingly.

    Best,

    Aaron