09-10-2019 05:45 AM - edited 09-10-2019 06:11 AM
I'm in the same boat as the rest of you and have been for about a year. There is no solid fix and some driver updates work for a bit but fail aftwards but it's more than just the flickering. These docks are so tempermental and one day my screen flickers the other my keyboard stops working I've even had the CAT5 cable not work from time to time.
I work for IT in a medium size business and we've moved form older T220's to the new X1 Carbons 5th and 6th gen. We are getting about 2 or 3 calls per day that something isn't working on these docks. I've tried all the suggestions from updating drivers to replacing equipment and some work for a little bit but the issues always seem to come back. I myself am on my 4th docking station and 5th computer and still having issues.
I wish we could go back to the old docking station that physically connected to the laptop.
09-11-2019 09:13 AM
I feel like this is some kind of trauma support group. My names Paul and I've been using a T470s on the TB3 doc for almost three years...
I've experienced almost all of the symptoms listed here. Screens shut off for two or three seconds, sometimes every few minutes, and sometimes every twenty or thirty minutes but sometimes it's fine for months.
Sometimes it will doc the laptop but never take input from keyboard and mouse. That is almost always resolved by undocking and redocking the laptop with the dock button.
I've always docked it closed screen with its own power supply. HDMI to DP factory cables included with dual HP monitors. Dock power is the big one that came with the dock. Laptop power (always connected) is the smaller travel adapter that came with the laptop.
The last time this was a big issue, moving the dock side of the TB cable to the front TB port on the dock fixed it for many months. That's all I did. It was also an issue very early on and that time the only thing I changed that stopped the flickering was literally just flipping the TB cabled ends, laptop to dock and dock to laptop. This most recent time I've noticed a big change in the frequency by just flipping the TB cable ends upside down. They had been branded side up, now they're blank side up, and this has reduced the frequency from every five minutes or so to once an hour or less and was the only thing I've changed. It doesn't make sense at all to me but the change in the frequency is dramatic and has always been the only change I've made.
I wanted to mention this because I hadn't noticed anyone saying they had replaced the TB cable itself or had similar experiences with just making basic changes to the orientation or using the front vs. rear port.
I plan on getting another cable and having it on hand to see if replacing the cable helps the next time it gets bad or eliminates it entirely.
Hope this helps some of my fellow TB Screen Flickering PTSD sufferers.
09-11-2019 03:39 PM
I have swapped the cable and the dock entirely to narrow down the issue and it hasn't helped. I haven't trying using the cable upside down as you mentioned, but I'll give that a try.
09-11-2019 04:25 PM
Like others in this thread I have done all the recommended updates, changed my cable, provided power to both the dock and my PC and nothing works. I still get the monitor flashng problem about once every 2-3 days. It is solved by unplugging my dock for a minute, and occassionally requires me to do both that and a reboot of my laptop. I am convinced the dock simply sucks - there is a hardware or firmware flaw that Lenovo has not or cannot fix. My plan is to buy another non-Lenovo TB3 dock and try that. If it works well I'll update the thread. If anyone had TB3 dock recommendations then let me know. Thanks.