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dgr4it's avatar
dgr4it
Iron Contributor
Jun 25, 2020

Touchback not working with USB-C display (Surface Hub 2S)

We just got two Surface Hub 2S at work, but I've been unable to make touch-back work on a single USB-C cable.   https://docs.microsoft.com/en-us/surface-hub/surface-hub-2s-connect, it's supposed to...
dgr4it's avatar
dgr4it
Iron Contributor
Jun 27, 2020

Thanks for the info cezarcretu 

I'm afraid however, tried both ways with both computers (only one cable this time around).

  1. Plug the USB-C cable after a fresh start (power from shutdown)
  2. Plug the USB-C while shutdown, then start the Surface Hub 2S

Unfortunately, still the same issue (have mailto:4k@60Hz video and power delivery, but touchback not working despite being recognize as "Guest Touchback Board" in the PC side.

 

Wonder if there might be a firmware update dealing with these issues, but since I have no admin rights to the Hub it's hard to tell if it's up to date or not.

cezarcretu's avatar
cezarcretu
Icon for Microsoft rankMicrosoft
Jun 29, 2020

Hello dgr4it,

 

Could you try with another USB-C cable or test with another device? 

If this returns the same behavior, kindly open a support case to investigate

 

Thank you,

Cezar 

  • dgr4it's avatar
    dgr4it
    Iron Contributor
    Jul 03, 2020

    cezarcretu One last question, on top of my previous question on the particular cable you linked.

     

    I have noticed that the https://docs.microsoft.com/en-us/surface-hub/surface-hub-2s-connect website lists the maximum resolution being mailto:4K@30Hz, whereas all the devices are mentioned were outputing mailto:4k@60Hz through the USB-C connection.

     

    Could it be that touch&pen back don't work when using 60Hz ?

    • cezarcretu's avatar
      cezarcretu
      Icon for Microsoft rankMicrosoft
      Jul 06, 2020

      Hello dgr4it,

       

      4K@60Hz is the output EDID from the Surface Hub to another device. Input is @30Hz .

      Are you connecting the USB-C cable in the compute module? What happens if you switch to one of the USB-C side ports? This won;t have 4K resolution but it would help to understand if it's related to 4K resolution.

      On the PC, can you see the Surface Hub in Device Manager?  

      • dgr4it's avatar
        dgr4it
        Iron Contributor
        Jul 10, 2020

        cezarcretu Actually, after so much testing on complicated scenarios, I have just discovered that Touch-back is simply not working at all.

        I always had the USB-C plugged when using Miracast, so I thought that's how I was getting pen & touchback, but I just didn't know Miracast could do that without USB.

         

        So in the end, I'll sum up my issue by:

        1. Touchback Host seems properly installed on the Hub2S (tried removing it and enabling it again)
        2. Touchback Guest properly installs on a wide array of devices, but only when using the Compute Module USB-C (none of the other ports react)
        3. There is no touch nor pen input no matter how I connect those devices. Tried :
          1. Both with the USB-C single cable and with HDMI display + USB-C for touchback on the compute module).
          2. A Surface Pro 7 on W10 1903, Lenovo T490S on 1909, and Intel NUK 10th gen on 2004
          3. A total of 3 different USB-C cables of the right spec.

        I'd guess there are only three possibilities left:

        1. There is an issue with both of the Hubs we got.
        2. Our IT guys applied some Group Policy which is blocking the touch functionality (probably unintended)
        3. The hub is missing some driver updates that might not be delivered because of WSUS policy)

         

        I'd love to know if there is an easy way to find out the cause.

  • dgr4it's avatar
    dgr4it
    Iron Contributor
    Jul 02, 2020

    cezarcretu I just got a 10th gen NUK PC to try, and unfortunately still not working, with any of the 2 Surface Hubs 2S we have. Really wondering if there is anything our IT department may have configured that is preventing this thing to work.

     

    For reference, I've tried the following 2 cables:

    • https://www.amazon.co.jp/gp/product/B0874HH4ZZ/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1 (the only one I still have with me)
    • https://www.amazon.co.jp/gp/product/B08835G2TJ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 (returned it to Amazon thinking it was a problem with the cable, even if now I'm quite sure it wasn't).

     

    And the following 3 PC's

    • https://www.lenovo.com/us/en/laptops/thinkpad/thinkpad-t-series/ThinkPad-T490s/p/22TP2TT490S (i7)
    • https://www.microsoft.com/en-us/p/surface-pro-7/8n17j0m5zzqs?activetab=overview (i5)
    • https://ark.intel.com/content/www/us/en/ark/products/189239/intel-nuc-10-performance-kit-nuc10i5fnh.html (i5)

    All of them are working with 4K displays (including the Hub2S), and with touch Full HD USB-C displays powered by USB-C but, for whatever reason, I can't get it on the Hub2S.

     

    Regarding the cable you posted, was that a random link or are you confident it should work with that cable? If it should work I can try buying it in Amazon JP as a last trial before submitting the ticket.

    • https://www.amazon.co.jp/UGREEN-Pro%E3%80%81Galaxy-Plus%E3%80%81Huawei-Pro%E3%80%81Xperia-XZ%E3%80%81Nintendo/dp/B07BTV4KJJ/ref=sr_1_7?__mk_ja_JP=%E3%82%AB%E3%82%BF%E3%82%AB%E3%83%8A&dchild=1&keywords=UGREEN+USB+C+3.1&qid=1593736813&sr=8-7.

     

    Daniel

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