12-04-2019 08:13 AM
This is a bug in Intel graphics driver 126.96.36.19929. We have withdrawn this version.
Please rollback to previous version here: https://pcsupport.lenovo.com/ch/en/products/laptops-and-netbooks/thinkpad-x-series-laptops/thinkpad-...
Sorry for this trouble.
I uninstalled the latest driver from Lenovo. Disconnected from the net. Rebooted. Installed the driver stated above and it still does not work on a plain Intel HD system. Unable to control brightness. Can we get a link to the last driver prior to 188.8.131.522 ?
12-04-2019 08:28 AM
Rolling back worked for me using 1.27 and set to Hybrid mode. I have tried Discrete mode again to see if brightness works with NVidia or not.
Lenovo, as a reminder, this is a SECOND GENERATION laptop. It should be stable and when it is not, there should be a sense of urgency to fix these issues. Some of us have paid upward of $3,000 for this laptop! Yet, we're still talking about issues that have been raised 3 months ago!
12-04-2019 08:39 AM
Agree. Mostly we purchase this machine as a reliable working tool, lenovo should be responsively aware of this kind of bugs that could greatly affect the working efficiency.
12-04-2019 08:47 AM
I understand your feedback. Honestly I am embarrassed for Lenovo about this problem.
I reproduced the problem here, and rolled back to previous driver, but still can't adjust the brightness. So currently I don't know what the solution is. I am working with the product team to get answers ASAP. Sorry for this trouble.
12-04-2019 09:18 AM - edited 12-04-2019 09:18 AM
The only working solution right now is to make a roll back in Windows to a day before installing the Intel Graphics update. Or a complete Windows reinstall.
We need a BIOS update to get it to work with new drivers. It's been a problem before, and was fixed with BIOS.
12-04-2019 11:47 AM - edited 12-04-2019 11:48 AM
I can't but agree. I've spent almost 4000 USD on my machine on which I depend on daily basis and it's been nothing but a huge letdown. Won't even mention their crappy TB3 docking station which should be pulled from the shelves and forbidden from ever being sold again. I'll never buy anything Lenovo ever again.
P.S. at least it didn't brick when flashing the BIOS like some other models apparently did, not yet anyway
12-06-2019 10:38 AM - edited 12-06-2019 10:53 AM
For those who don't want to run in Discrete mode but do have access to an external display, I found a semi-workaround to the inoperable brightness control issue, which unfortunately persists on my system after rolling back from the now-retracted driver to the now-current driver. I wrote it up in this post in another thread about lag on external displays, since it seems these issues are linked somehow.
UPDATE: It seems I may have permanently regained brightness control, i.e. without needing to continue using a workaround, after rolling back to the older Intel Graphics version -- even though the rollback initially didn't restore brightness control. See linked post.