I had my laptop, which is an HP Envy 15 ae116tx model, fixed in a service center because of screen discoloration (it's a touchscreen btw). They replaced the display panel. I got it back after a month and I noticed that the screen brightness control is not working anymore. The brightness control in the taskbar is greyed out and cannot be adjusted, the function keys in the keyboard are not adjusting the brightness as well, and there's no adjustment slider in the power options.
Adjust Laptop Brightness is a tuning utility to change screen brightness on laptop, notebook, netbook, and ultrabook. It helps you to save your battery and your eyes as well as the back light of.
I've searched online and tried any possible solution there is, but unfortunately, none of them worked for me. I'm very frustrated now and I don't know what to do. The following are the solutions I tried:
DEVICE MANAGER SOLUTIONS
1.) Updated the display driver as suggested, it did not work.
2.) Disabled and enabled the display driver, it did not work.
3.) Uninstalled the display driver and reinstalled it, rebooted my laptop, still it didn't work.
4.) Disabled and enabled the Generic PnP Monitor, it didn't work (it was enabled in the first place btw).
5.) Uninstalled and reinstalled the Generic PnP Monitor driver, still didn't work. I also clicked 'show hidden devices' and uninstalled all the drivers under Monitor, including the hidden ones, reinstalled them and still didn't work.
6.) I rolled back to the old versions of my display drivers, still didn't work.
7.) I switched to Microsoft Basic Display Adapter, brightness still cannot be adjusted.
OTHER SOLUTIONS
1.) I updated my Windows, installed the anniversary update. I installed and updated all suggested updates in the Windows Update tab, but it didn't fix the brightness control problem.
2.) I did the regedit solution, there's no KMD_EnableBrightnessInterface2, so I made one up and restarted my laptop, still didn't work.
3.) I can't remember where I found this solution, but I did something about changing a value for a key/sub-key in regedit.
I did more solutions as I can remember, but none of them really worked. I considered refreshing my operating system in hopes of making the screen brightness adjustment work, but I want to know if there are more other options. Since I had the display panel replaced for my laptop, I don't know if it has something to do with that.
Also, I can only adjust the brightness manually with the Intel HD Graphics Control Panel but of course, I don't want to resort to that since I still don't get the default screen brightness control. If nothing really works, I might have to contact the service center again to ask for a solution.
I hope someone can help me. I'm really exhausted looking for other options.