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What's wrong with my LCD

Discussion in 'Troubleshooting' started by Carlos144Green, Jan 23, 2023 at 5:59 PM.

  1. Carlos144Green

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    I happened to mess up the video output on my LCD screen a very very long time ago. I don't remember if it was me updating the roboOS or if it was me shorting something and breaking it. The setup my LCD screen came with was just a metallic ribbon cable from the Pi to the LCD but I forgot in which orientation it went in, leading past me to perhaps short something.

    I did some fiddling around and used a spare HDMI cable I had laying around to test the LCD. It shows the menu just fine but the touch input doesn't work.

    I suspect one or more of these three things:
    1. That the pins are either not working anymore because I shorted them
    2. That I just don't have the ribbon plug in the right orientation
    3. I potentially flashed a roboOS that doesn't allow my old ribbon plug to work anymore
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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  3. Lance Weston

    Lance Weston Active Member

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    I have found that the HDMI cable is hairy and causes me problems. Partsbuilt.com has a new design HDMI cable that has fixed that. I have put it in all of my R2's.
     
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  4. Carlos144Green

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    So I managed to make the LCD screen turn on but the touch is not working still. I even bought a replacement LCD here and that was the same thing, visual but not touch-responsive.
     
  5. Carlos144Green

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    Could this be a pin problem? I want to try to swap out the pi entirely but 1. That is difficult so I much rather try simpler solutions first and 2. I don't know the steps to swap a pi out
     
  6. Lance Weston

    Lance Weston Active Member

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    The touchscreen does not come across the HDMI. It uses the other connector. So it could be a bad connector or Raspberry Pi. Read the attached manual.
     

    Attached Files:

  7. Carlos144Green

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    Yes, this is clear to me. The HDMI cable is not the problem. The problem is that there is no touch *with* the ribbon cable from the pins of the pi plugged in.
     
  8. Lance Weston

    Lance Weston Active Member

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    The LCD display came with an HDMI connector. You can lift out the Raspberry Pi and directly connect a display to it using the HDMI jumper. That removes the IDC connector from the equation. Just use the power connector. It is awkward but will allow you to test the display and verify that the IDC connector is the problem.
     
  9. Carlos144Green

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    So I removed the ICD connector from the LCD and just have the LCD screen as a hat for the raspberry. It's still not responsive to touch. I'm going to swap the pi out for a new one. Is there a guide for this?
     
  10. Carlos144Green

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    I tried to replace the pi for a 3b+ with the same unmodified sd card and it didn't work (no surprise)... I didn't even get the Robo screen, just the colorful default rgb gradient screen
     
  11. Lance Weston

    Lance Weston Active Member

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    I think it is more likely a bad SD card Image. Try burning this image to a 16mB Sandisk SD card.
    To Burn Image:
    https://drive.google.com/file/d/1o6Y_jwGPM3XeRI1E-sb3Y2swW8ra8D9U/view?usp=share_link
    Image:
    https://drive.google.com/file/d/1RM7due607CQg3A5QX2bU0HkiJWkx2BEe/view?usp=share_link
     

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