11-29-2018 05:31 PM
One of the staff I support is using a Lenovo Thinkpad USB-C dock.
Currently the ethernet connection runs into the desk phone, then from the desk phone out to the dock.
For some reason, when he has the dock connected to his laptop via USB-C, the ethernet connection is not detected by Windows.
Things I've checked:
* Checked all other items connected to the port (two monitors via display port, USB keyboard, USB mouse) and they all work fine
* Checked the port on the rear of the dock, LAN activity lights are flashing, so there is data passing through to the dock
* Tried bypassing the phone and connecting the ethernet line directly in to the dock, didn't solve the issue
* Tried connecting the dock to the second USB-C port, didn't solve the issue
* Tried testing with a regular Lenovo ethernet dongle, and that worked fine - so it's not an issue with the LAN connection or cable
* Tried installing the latest drivers and firmware for the dock, in both cases I got a message saying the latest software was already installed
Having no other ideas I called Lenovo support and they sent out a replacement dock. I swapped that out, and have the exact same issue - so it doesn't look like the dock is faulty.
I have no idea what else to try.
03-26-2019 06:11 AM
We use the 40A4 for the Yoga-260, and have had similar if not the exact same issue. I've done everything from swapping the dock, power supply, ethernet cables. I've updated ALL the firmware. Sometimes switching the dock will allow ethernet to connect, but eventually it does revert back to no LAN connection.
Ultimately, I've just had to buy 3rd party USB Ethernet dongles, those seem to work for now.
04-12-2019 01:03 AM
We've got this exact same issue.
We've just purchased 300 of these USB-C Docks 40AS Type but when connecting via Ethernet it display lights on the port but on laptop it says cable is unplugged.
This is becoming a big problem, any ideas on a fix?
07-24-2019 04:32 PM
Welcome to the community forums.
Found this Lenovo Forum thread that has the same issue that you have. Click this link: https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T480-No-Ethernet-wired-network-when-dock...
Make sure to check the compatibility of the docking station to the laptop that you are using. To know more information about it. Please go to Hardware Compatibility section of this support page: https://support.lenovo.com/us/en/accessories/acc100348