NO SIGNAL when connecting secondary screen to Chromebook

Hi!

I have the followings setup.

When I connect the screen through the docking station to my Chromebook’s USB-C port I get NO SIGNAL (Blue screen). Connecting the screen directly to the Chromebook using the same cable works perfectly. In the first setup the computer charges perfectly.

What could be wrong?

Hello @CEdv and thank you for your interest in our Community.

From what I can see, your portable monitor requires 5V/2.4A (12W), while the DKM31C3HVCPD downstream USB-C video port supports up to 10W. That difference is likely why the display works when connected directly to the Chromebook, but not through the dock.

A closer match would be the HB31C3A1CDPPD3, since its downstream USB-C port supports DP Alt Mode video and up to 12W when connected to a USB-C power adapter. However, it would still be at the upper end of the monitor’s power needs.

To help ensure reliable operation with our travel docks, our recommendation would be to power the monitor independently from the dock.

I hope this helps!

Emmanuel B.
StarTech.com Support

Thank you for your support Emmanuel.

I tried connecting an external power source (5V/2.4A) to the Yodoit screen as suggested. This results in the same problem (“No signal”). I tried two different setups based on this, either trying to get video through the HDMI or the USB-C. Dock is connected to the Chromebook’s power adapter in both cases. I will try with a more powerful external power source, as I don’t trust the 5V/2.4A spec.

But,

Is there a known EDID/handshake issue or firmware fix for this problem if known?

Solved.

I now tried simply connecting my Chromebook’s power supply directly to the first USB-C port on the Yodoit screen, and then run a USB-C through to the Chromebook. This worked and should confirm the issue with a low power supply as you suggested @EmmanuelB, thank you for your help.

I liked the format of the DKM31C3HVCPD, but will sadly have to return it as it then doesn’t fit the needs for my current setup.

Thank you for your support.

Hello @CEdv , thank you for your return.

We certainly understand. Your best bet is to verify that the solution you opt for can support 15W USB-C output to better mimic the capabilities of a direct computer connection.

Sorry for the inconvenience and thank you for looking with us for a solution.

Emmanuel B.
StarTech.com Support