After upgrading Windows 10 to 1809 on our Lenovo T470, the system only shows a black screen after boot.
I can log in using Remote Desktop, but neither the notebooks monitor, nor an external monitor show the screen. The external monitor's LED indicates a signal though.
The issue can be reproduced with other T470. I tried the newest graphics driver from Lenovo (18.104.22.16886), an older one (22.214.171.12423) as well as the current driver from Intel (126.96.36.19919). To install the Intel driver I completely removed the Lenovo drivers first, so only the Basic Display driver was installed.
With the basic display adapter as well as with an older Lenovo driver (188.8.131.5273) the system works as expected.