Lenovo T470 no longer dual-montiors

[Certifiable]

I have a T470 20HD running Windows 10 Pro. Both the operating system and all Lenovo updates have been applied.

Attached to this is a Plugable UD-ULTCDL docking station that’s been driving a pair of Dell SE2417HG(HDMI2) screens, a USB headset, and a wired keyboard and mouse.

Or did. Now only drives a single screen. Windows used to see both displays and deactivated one, but now claims it only seesonly the right-side Dell display. I’ve tested both displays and they work fine otherwise.

I’ve grabbed the latest Intel Driver for the laptop’s video, which very temporarily (read: One reboot) got back control of both screens, but now the left screen doesn’t want to play at all.

I’ve certainly open to suggestions on how to get this to work again.

Thanks!

[EDIT] Yes, I’ve already powered it all down, tested all connections are solid, and did the plug-things-in-one-at-a-time dance already. If I plug in the left monitor first, it only detects that one. It’s first-come-first-served for the external monitors.

[Joshua_H]

Hello,

Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.

Let’s start by doing a full clean install of the DisplayLink drivers and see if that helps at all. Here’s how:

1. Disconnect the dock from the system and please remove the power cable from the dock so it turns off completely. Please keep it disconnected until the last step.

2. Uninstall any and all software with ‘DisplayLink’ in the title that is present from within the Control Panel -> Programs and Features. Don’t worry if these entries are not present or if the process does not work, just move onto the next step.

3. Download, extract and run the DisplayLink cleaner tool, found here –> http://www.displaylink.com/downloads/file?d=64 and ensure it displays “Cleaning Complete”
   when done (video walk-through if you need it -> https://youtu.be/AcVV1gD_FvI)

4. Once the Cleaner has been run, reboot (even if not prompted to)

5. Now download and install the 9.1 M0 DisplayLink software, found here –> https://www.displaylink.com/downloads/file?id=1326

6. Reattach the power cable to the dock first. Once the dock is powered on, reconnect it to your system which will trigger the final portion of the installation. If the device is not detected, please reboot the system.

If that still doesn’t seem to work, we have a troubleshooting tool that helps us find out what is going on in situations like this. Please plug the dock with both monitors attached into your computer, then go to this page and follow the instructions there:
http://plugable.com/support/plugdebug

Please don’t hesitate to let us know of other questions.

Thanks again for contacting Plugable support and best wishes!

Joshua Henry

Senior Engineer
Plugable Technologies

http://plugable.com | http://performance.plugable.com/

[Certifiable]

No joy after completing all steps. Sent debug to support.

[Certifiable]

Any updates on the debug report?

[Joshua_H]

Hello!

We replied to your email with the diagnostics on Apr 10 at 15:55. It sounds like perhaps you didn’t receive our reply. We’ll resend our reply, be sure to check your spam folder if you don’t see it!

Thanks!

[Certifiable]

Hmm. Checked my junk folder and everything, but never seems to get the original mail. Oh, well.

For the public, here’s the important parts:

A few things we can try after looking at the diagnostics. The Intel drivers still look a little old, currently 24.20.100.6286 is installed and the most recent ones from Intel are 25.20.100.6618 that we can try: https://downloadmirror.intel.com/28646/a08/dch_igcc_win64_25.20.100.6618.exe

I just updated the driver, but no better.

Then for my knowledge, when the diagnostics were run, do you recall where the screen that is working was connected? To the 2K HDMI or the 4K HDMI port? And lastly for your knowledge, the HDMI 4K port is driven by the Intel graphics card in your laptop utilizing USB-C VESA Alternate Mode video output and the 2K HDMI port (and DVI port) are driven by the DisplayLink DL-6950 USB graphics chipset in the dock.

I was using the 2K port, but tested to see if the 4K port also still worked - unplugging one HDMI cable caused the other screen to come online and stay online, but then the original one wasn’t detected.
I just updated the driver, but no better. At that point I tried to do a manual cutover to the right-side (2K port) screen

I might also recommend “disconnecting” (within Windows display settings) the extended display(s) so that only the laptop screen is active. Then disconnect the dock, leave it disconnected, and reboot the system. Once it comes back, go ahead and try to extend the monitors again and see if that makes any difference. It sounds like we may be hitting a Windows issue where the display configuration has been left in a bad state. In addition, I can confirm that the DisplayLink reinstallation appears to have gone successfully as I now see DisplayLink 9.1.1462.0 is installed. So thanks for doing that!

I did as you said and found the 2k cable at the dock was loose! Once I fully seated that all was good again.

So, I’m guessing it was a combination up updates and finally finding the loose cable (apparently loosened during my troubleshooting) as a win.

Thanks for all the help!

[Certifiable]

Just wanted to report in - aside from a single incident of the left side monitor not being detected - and corrected with a Windows display control panel adjustment - it’s all been running perfectly.

Thanks again!