USB-C/Thunderbolt Dock Megathread

Hi, @D_Smith, @Foxtrek_64, @Alec_Jurisch, @Antoine_Chatelain

I would like to know if people who have this USB-C dock base can reproduce the issue I’m facing with the FW 13 AMD or FW 13 Intel.

TL;DR

Every devices works beside the external screen that is plugged via HDMI on the USB-C dock.
The external screen works with a Lenovo Thinkpad T495 laptop but doesn’t with the FW 13 AMD.
However, if I plug the T495 and then unplug and plug the FW 13 AMD, the external screen starts working on the FW 13 AMD and also other laptops (an Intel one).

I have an interesting finding with the Thinkpad USB-C Gen 2 AS40 (I will confirm the exact model number in a coming edit), if I plug in my Lenovo T495 AMD laptop on the USB-C dock, the screen and USB devices work.

Then, if I suspend the Lenovo laptop and unplug the USB-C dock and plug it into the AMD FW 13, the external screen plugged into the dock do not come on.

However, if :

  • Plug T495 on the USB-C Dock Gen 2
  • Unplug the T495 (do not suspend the laptop while having the Dock plugged in else it won’t work)
  • Plug the AMD FW 13, the external screen works.

Important note during my testing : I have tested this with a 60W charger plugged into the FW 13 AMD on one side and on the other side, I was plugging the USB-C dock, thus the USB-C dock wasn’t providing power.

I have also reproduced this issue/workaround with another Dell Intel 12th gen laptop.

I wonder how I can investigate more thoroughly, or if I need something like an USB-C logic analyzer thingy to capture the USB communication.

EDIT :
Suspending the Lenovo T495 Laptop while being plugged to the Lenovo USB-C dock gen 2, breaks the external screen for the next laptop that gets plugged in if it isn’t a Lenovo laptop, not sure what’s going on.