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

Iron Contributor

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.

 

In theory, it's supposed to deliver power, 4K display, and touch-back (pen included) through a single USB-C 3.1 Gen-2 cable, and yet so far I've tried:

  1. Two different and brand new USB-C cables (relatively premium, 3.1 Gen 2 spec)
  2. Two different devices (Surface Pro 7 on USB-C, and Lenovo t490s on both USB-C and Thunderbolt3 ports)

And yet, I'm always getting Power + 4K@60Hz display, but no touchback (nor pen).

If I connect through Miracast and plug the USB-C I can get both display and touch-back, but resolution is dismal and Miracast lag makes it hard to enjoy the "touch-pen" experience.

 

Is there anything I'm missing?

Any idea or advice?

 

Thanks in advance, 

 

Daniel

 

PS: Both computers detect a "Guest Touchback Board" input device, which shows in Device Settings, and both of them recognize the Surface Hub 2s as some kind of Touch panel with "limited functionality"

 

15 Replies

Hello Daniel,

 

This is something we're looking at. Seems like this happens after the device resumes from sleep. Can you try to restart just to confirm that you have the same behavior?

 

Thank you,

Cezar

Should I keep the USB-C plugged when restarting ?
Or simply ensure I plug the USB-C cable after a fresh start ?
(I'll check it out tomorrow morning Japan time)

hi @dgr4it,

 

If I understood it well, plug in the USB-C after the restart but would help if you could try both

 

Thank you,

Cezar

 

Thanks for the info @Cezar Cretu 

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 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.

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 

@Cezar Cretu 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:

  • Nimaso cable (the only one I still have with me)
  • iVANKY cable (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

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.

 

Daniel

@Cezar Cretu One last question, on top of my previous question on the particular cable you linked.

 

I have noticed that the relevant docs.microsoft website lists the maximum resolution being 4K@30Hz, whereas all the devices are mentioned were outputing 4k@60Hz through the USB-C connection.

 

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

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?  

@Cezar Cretu I tried quite a few more things on the Surface Pro 7 (W10 1903) today.

Please see the attached screenshots but, in short:

  • Yes, I am connecting the USB-C cable on the Compute Module, since there is no video (at all) on any other connector.
  • I know the Hub 2S is supposed to be 4K@30Hz, but using the recommended resolution which is automatically identified by any device I've tried (3672 x 2448), it sets up at 60Hz (and you can tell by the responsivity that it's indeed 60Hz)

SurfaceHub2S_USB-Cinput60Hz.png

  • When using the maximum available resolution (3840 x 2560) then it goes at 30Hz.

SurfaceHub2S_USB-Cinput30Hz.png

  • I can't get touch-pen to work no matter which resolution I use when using the USB-C Gen2 cables linked before, despite the Surface Hub being properly recognized (or so I believe, please check the attachments).

SurfaceHub2S_PluggedToSurfacePro7_USB-C_1.png

SurfaceHub2S_PluggedToSurfacePro7_USB-C_2.png

 

  • If I connect through Miracast, and then use the USB-C cable for Pen-Touch, then it works without problems.
  • On a very weird procedure, after connecting through Miracast + lateral USB-C I tried hot-unplugging the USB-C cable from a lateral connector and pugging it into the Compute Module, without disconnecting Miracast. In that case, it seemed that the screen switched to USB-C and I was finally getting Video+Touch&Pen, but settings became very unstable (resolution was not properly detected) and I'm not sure if it wasn't simply misreporting the input device.

I'll try a bit more tomorrow on the Miracast-to-USB-C switch, out of curiosity, and even if this is certainly not how I expected the expensive Hub 2S to behave. It should really be plug & play for it to make sense.

 

I keep wondering if there isn't any software/firmware update that our IT might be blocking out of ignorance... Would appreciate if you have any info on that area.

@Cezar Cretu 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.

Hello @dgr4it,

 

So to sum it up, you tried to use a single USB-C cable connected to the compute cartridge and to a laptop and touchback/inkback did not work. You also tried to use a HDMI cable and USB-C cable to another laptop and still no luck.

It should work seamlessly so it does look like something is blocking it. Can you please open a case so we can address this in a remote session? If you're in EMEA time, I'd be happy to give you a call

 

Thank you,

Cezar

@Cezar Cretu Thank you for the follow up.

Unfortunately, I don't have the required admin rights on this tenant (which is in Japan, btw), but I will pass the info gathered here to the relevant instances, and hopefully they can get it fixed.

Hello @dgr4it,

 

Unfortunately the time zone difference won;t be of help but my colleagues handling APAC will be happy to help

 

Best regards,

Cezar  

@dgr4it did you ever find a fix for this?

@ERay70 I'm afraid I didn't, but I don't have the Surface Hub to play around anymore (our company just gave up on it, and since then I've moved somewhere else).