06-18-2018 12:53 PM
I'm using a USB-C to HDMI adapter (using the DisplayPort over USB standard, not an older DisplayLink type) to use an external display on the Yoga 730 and it has issues when running as 2 separate displays (everything works fine when mirroring or using only the external display). If you set the graphics settings to "extend these displays" the Windows 10 shell seems to wedge itself (can interact with already running apps, but cannot start new apps or use the taskbar/start menu) and the bottom of each display flickers (looks like a flickering ghost taskbar).
I don't suspect a hardware issue with the adapter because it works perfectly in mirroring or single-display mode; instead I suspect a graphics driver bug. Others that use this adapter on other PCs have no problems. I'd love to try a newer version of the Intel 620 graphics driver but it won't install (it says it's incompatible with this system and to contact the computer manufacturer)... Lenovo's customized version of the driver is 4 months old.
I have all the latest drivers installed via Lenovo Vantage, Intel's web interface (it only installed newer Wifi and Bluetooth drivers), and Windows Update. The laptop is running Windows 10 1803 17134.112 (2018 Creator's update).
06-29-2018 12:45 PM
I forgot to mention that this is the 13 inch version, though I think the 15 inch internals are more or less identical.
I tried manually updating the graphics driver from Device Manager and it detected and installed the 22.214.171.12494 driver from Windows Update (I don't know why the main Windows Update UX wouldn't detect and install it or why Lenovo Vantage doesn't list the newer driver). However, this version did not fix the behavior when extending the displays. The release notes for 126.96.36.19936 on Intel's website shows "Improved detection of type-c and Thunderbolt™ displays" as a feature update, so that has a chance of fixing the issue when available, but I won't hold my breath.
06-29-2018 02:12 PM
I tried playing with different variables: different monitors, cables, resolutions, etc. and I found the problems all revolve around making the external display the primary display. The worst behavior is what I saw, and it requires the external display to be set as the primary display and be positioned above the laptop's internal display. I saw similar but less severe behavior when the external display was primary but configured to be positioned below or to the sides of the internal display (task bar came back but start menu was not functional).
This has been infuriating but I am now resigned to just run the internal display as primary and drag apps to the [bigger] external display whenever I plug it in (tedious).
08-08-2018 06:34 AM
Thanks for the post - I am having a hard time even getting my current adapter to display the monitor. Can you confirm that the adapter you included in your post does indeed work to display the yoga 730? Any recommended display driver update?
09-04-2018 03:21 PM
Did you ever get this figured out? I'm having the same problem.
On the NVIDIA card I can only get the laptop screen to work, no external monitor detected via HDMI, but if I enable the built in Intel 620 graphics adapter it detects the external monitor no problem, but then both monitors work off the Intel card and I can't switch the laptop screen back tot he NVIDIA card.
Super frustrating. If you figured it out let me know. Starting to regret buying this thing.
09-04-2018 05:24 PM
I am beyond frustrated. I have worked with support repeatedly to get drivers updated as well as bios. I have bought new cables interfaces and nothing works. The last support agent informed me that it should work which was not very comforting. Appeared to be a great laptop but also does not support external monitors. If you’re buying this for External managers save yourself the headache and out I’m going to return mine. Lenovo didn’t stand behind the product as advertised. Guess I should have stayed with Dell or HP