04-04-2017 10:07 PM
I have looked long and hard at other peoples' solutions to this problem to no success.
I have tried:
-installing latest Intel HD 5500 driver from Lenovo site.
-installing latest beta driver from Intel
-enabllng the Generic PnP Display
-Several registry hacks that claimed to work (I reverted back after they failed to do anything)
My question is, when will the display driver support brightness settings again, or is there an older version that works that I can download? I can't "roll-back" my display driver, as the current one was the first I used. Using the default Microsoft VGA driver is a non-starter. I need proper resolution.
If anyone can help, I would appreciate it. I feel like I have tried every solution on the internet, and perhaps the only solution for me is a different driver, possibly. Or one that doesn't exist yet.
04-05-2017 05:33 PM
While I know this problem on X1 Carbon 4th-gen, and X1 Yoga 1st-gen, I have never heard it on X250 or any other model. And the known problem on the X1 models can't possibly happen on X250. So I'm really stumped.
Is there anything unique about your setup? Are you using the Lenovo factory preload or is it your own Win10 installation?
Can you export the registry at "HKEY_LOCAL_MACHINE\Software\Intel", zip it up, and post it here? Or if you can't attach it here for some reason, please upload it to onedrive/dropbox/etc and share the link.
04-06-2017 06:44 AM
Here is the registry dump. And I bought the system used, and the previous owner did a fresh install of vanilla Windows 10, not the windows 7 the system came with. All of the buttons worked when I turned on the system for the first time, then I started downloading all the Windows updates. After the "Anniversary" 1607 update, that is when only the brightness keys stopped working. All other hotkeys work. The Windows system itself does not allow you to change the brightness, as the battery charm (when clicking on the battery in the system tray) has the option button greyed out. According to other websites, similar sysptoms occur on other manufacturers' models as well. The problem is different from the X1 problem, in that I don't get color weirdness or screen blanking, just unable to change brightness at all.
Thanks for the quick reply.
04-06-2017 11:03 AM
I received the registry dump, imported it into my X250 Win10 test system and rebooted, and found that the brightness keys still work. And I am also able to adjust brightness using the slider control in Display Settings. So I really have no idea what the problem could be with your system. I know it's a pain, but this is the type of random problem (that nobody else seems to have) that is sometimes best solved by reinstalling Windows. Especially on a used system, it's a good idea to start with a clean slate. Anyway, I'm sorry to say that I don't have any other advice.
11-08-2017 11:57 PM
I am having the exact same problem, so, it is not a one off. Tried all the solutions found online with no luck. Updated driver, uninstalled generic driver, everything listed in the intial post of this thread and no luck. But I do know that he is not alone.
01-01-2018 12:40 PM
Exact same problem here on an X250 recently purchased used, after installing Windows 10 Creators Update. Tried all solutions discussed here except a full Windows reinstall.
03-29-2018 12:05 PM
I have the same problem with an Ideapad 100, if I allow Windows to update the display driver to Intel HD 5500 the computer crashes with a blue screen message "VIDEO TDR FAILURE igdkmd64.sys" so I have to start Windows 10 in safe mode and delete the driver through device manager so I can restart in normal mode. I tried updating the driver with the one on the Lenovo website so that I could adjust the screen brightness which is stuck on 100% with no way of dimming it.