PanelDue 5i touch location is off towards the right



  • This is the PanelDue on my CNC machine. It was working fine earlier today, and I did a long job.

    After the job completed, I noticed that the screen was hanging skew inside its enclosure. I figured the nuts holding it in place vibrated off, and decided to replace them with loc-nuts so that it will not happen anymore.

    After the fix, all touch events register on the right edge of the display. If I tap on a home button, it will load the Macro screen. If I tap on any other screen tab at the bottom, it goes to the Config screen (and I simply can't return). I can't run a display calibration, since I can't tap the button for it, it rather takes the rotate option, and I can't touch on the dots.

    This issue have happened to me before, and to solve it I simply ensured that nothing touches the close to the display and the screen wires (the orange ribbons) and then it would work correctly. Now, I have completely disconnected the display from the enclosure, but the same issue.

    Any ideas for what I can try?



  • Setup->Calibrate Touch or Setup->Invert Display on the PanelDue, should get the calibration routine going.



  • That is a part of the problem. All touch goes to the right hand side of the display (side with the reset button). Even when inside the rotate routine, I can't touch the dots, because it thinks I touch way off them so it is ignored.



  • Reset or maybe reflash the firmware otherwise something is wrong with the touch stuff. Check the ribbons on it.



  • I have now reflashed the firmware (still using the latest version available), and it still happens. I checked the orange ribbon wires, I don't see anything that stands out as a cause, but I don't exactly know what to look for.

    As I understand there are 3 sets of ribbon wires: the display is the large wide ribbon, the backlight is the 2 wire ribbon and the 4 wire which looks like it is the touch. I am not sure how the 4 wires work for the touch, but I don't see any specific damage to it.

    Originally my enclosure had a tight fitting, but in order to solve this issue earlier, I had to modify the enclosure to give more space around the ribbon wires (nothing could touch the ribbon, or touch would trigger to the right).


  • administrators

    It sounds to me that either the touch membrane has failed, or the 4-way connector from it isn't making good contact in the socket on the LCD main PCB. You could try unplugging and re-inserting the 4-way connector.



  • On the display, the 4 wires appear to be soldered to the wide orange ribbon. Attaching a photo. 0_1539987041017_touchscreen.jpg

    The solder joint seems good.

    If the membrane failed, where can I get a new one?


  • administrators

    Is the connector in the bottom of your photo fully inserted? I think the right-most 4 pins connect the touch membrane.



  • I disconnected and reconnected that connector. It seemed to be fully seated before and after, but still no functioning touch.


  • administrators

    I guess it's worth inspecting the 4-way flex cable and the soldering for damage or likely bad joints. If there is no damage and your PanelDue is under warranty, ask for a replacement. Otherwise, somebody else replaced a faulty touch membane on his/her display, see https://forum.duet3d.com/topic/4362/paneldue-screen-broken/7.



  • I think I found the cause: the glass at the bottom left have a very small crack (diagonal from ~7mm from left to 7mm from bottom). It runs just below the white line, not near the display area. I have to shine a light at the right angle to see it.

    I don't understand why it would crack there. I have never dropped the screen or abused it in any way and was bought little less than 2 months ago. From close to the beginning (when I first inserted it into the enclosure, I first noticed it) I had the issue, but did not think too much about it and it was solved by ensuring the touch ribbon was running freely. Since then it worked up to today after replacing the nuts with loc-nuts (in the position it was in, when I found it have lost 2 nuts, it can't damage itself as the enclosure have ample space behind [it was still connected by 2 nuts on the right hand side], and the display was tilted upwards, so the nuts would simply have fallen away and not damage anything).

    Installing the loc-nuts was also done with caution, knowing that I may have a touch issue if they are too tight. When I first found the issue after installing the loc-nuts, I checked to ensure they are not too tight, and they weren't.



  • Having done a bunch of research since, I figured out that due to the way 4-wire resistive touch panels work, if the X or Y layer is damaged, you will get similar results - the damaged layer will be unable to determine a position and will therefore be right at an edge.

    The damaged edge is the thin glass outside of the metal casing. So I think that only the touch part is damaged.

    Me being in South Africa just makes it difficult and expensive to bring in replacement parts.

    Looking on the PanelDue board, I found the buydisplay.com markings, so I checked there. It seems that the actual display on my PanelDue is the one at https://www.buydisplay.com/default/5-tft-lcd-display-module-wvga-800x480-high-resolution-for-mp4-gps. Is this correct? If I can only replace the touch panel, will this one work https://www.buydisplay.com/default/5-inch-resistive-touch-panel-screen?

    Since may PanelDue is the integrated version of the 5".
    Would simply replacing the touch panel work (cheapest and possibly easiest option)? How would I remove the broken touch panel? Do I simply peel it off? How do I ensure I place the new one perfectly on its place?

    Or should I rather opt to replace the whole display and touch panel as a unit (the more expensive option)? In this case, how do I separate the display from the PCB? Is it soldered or glued (what glue and what can be used to stop it from keeping the old one) in place?

    Just trying to get all the information I will need to fix this.


  • administrators

    @jacotheron said in PanelDue 5i touch location is off towards the right:

    Looking on the PanelDue board, I found the buydisplay.com markings, so I checked there. It seems that the actual display on my PanelDue is the one at https://www.buydisplay.com/default/5-tft-lcd-display-module-wvga-800x480-high-resolution-for-mp4-gps. Is this correct? If I can only replace the touch panel, will this one work https://www.buydisplay.com/default/5-inch-resistive-touch-panel-screen?

    That looks like the right one.

    Since may PanelDue is the integrated version of the 5".
    Would simply replacing the touch panel work (cheapest and possibly easiest option)? How would I remove the broken touch panel? Do I simply peel it off? How do I ensure I place the new one perfectly on its place?

    I don't know because I've never tried it. But see the other post that I linked to earlier from someone who has done it.

    Or should I rather opt to replace the whole display and touch panel as a unit (the more expensive option)? In this case, how do I separate the display from the PCB? Is it soldered or glued (what glue and what can be used to stop it from keeping the old one) in place?

    I think that would be more difficult.



  • My replacement touch panel came in today, and I have performed the swap.

    For other people wanting to perform the same fix, here is how I did it and recommendations:

    • First step is to desolder the touch panel from the display ribbon cable. If you have a hot-air station, this is easy (all 4 contacts need to be desoldered at the same time). Since I don't have such a station, and my touch panel is broken, I simply cut the touch panel's ribbon off, to get desolder under the ribbon.
    • Next, we need to remove the broken touch panel. I used a small exacto knife to do this. You want to slide it in carefully, between the metal frame of the TFT LCD panel and the glass of the touch panel. The touch panel is held only one the sides, so you don't have to insert the knife further than the TFT's metal frame. Also be careful for the film on the TFT panel, that supports the touch panel from below. You do not want to stress the touch panel glass - it is thin and very fragile, when breaking, it creates a bunch of glass dust. If it breaks remove it carefully - do not scratch the TFT panel.
    • Now we can clean the TFT panel from the adhesive residue. I used a bit of rubbing alcohol, but that turned out to not be a very good idea. It seems some of the alcohol got in behind or on the backlight (now mine have different whites in the bacground - hopefully it can evaporate and restore it to a single white). Also a good idea to wipe any dust before we continue - you do not want any dust below the touch panel.
    • The new touch panel can now be prepared. The panel comes with a protective cover on the front - this can be left in to help protect the touch panel. The panel also comes with a back protective cover, with a tab to peel it off - this can now be carefully removed. The adhesive is only on the edges, so do not touch the center.
    • Align the touch panel over the TFT panel, with the ribbon going out the right way, then lay it flat on the TFT panel. When it is on, press the touch panel on the edges for the adhesive to take.
    • Finally you can solder the touch panel's ribbon back on. I used a piece of tape to keep it in place while I solder it.

    With everything back in place, power the display with USB, and test out the touch. If it works, run the touch calibration.


  • administrators

    Thanks for the write-up!


 

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