12-24-2017 11:54 PM
There are tons of "solved" and unsolved HDMI / Display Port without audio issues. Long story short:
1> Control Panel -> Sound -> Right click "HD Audio" option and set it as default output. Done.
2> If no "HD Audio" option can be found, ensure your notebook has"HDMI / DP output" features shown in Lenovo hardware compatible matrix.
3> If it is compatible, in Control Panel -> Device Manager -> Display Card -> Right click "Intel HD XXX" -> Uninstall -> Delete driver -> Reboot. This will let you use "Standard VGA" driver, and you will found "HD Audio" option again, and it sounds!
Attached image showing "HD Audio" option in the sound panel when using "Standard VGA Adapter driver" while it is hidden when using "Intel HD XXX driver"
This looks like issue of Intel display driver. Hope there is another driver update to solve.