Can not adjust Brightness in Windows 10

Ah yes, I should have known it was the old 4d36e968-e325-11ce-bfc1-0 8002be10318 issue. :-)

No settings that you mention:

Doesn't this still indicate my original suspicion that the driver is not right? Brightness can change, but Windows doesn't see that it can so the Windows settings doesn't have a slide bar and the buttons don't work.

Thanks,

Dave

Logically, if El Capitan+W7 or El Capitan+W10 worked, and you upgraded to Sierra, it does not impact any BC/W7 or BC/W10 drivers. The other changes are in Sierra (or some EFI firmware).

As a test, can you install El Capitan on an external disk - How to set up and use an external Mac startup disk - Apple Support - and boot from this disk and check if you can switch to W7 or W10 and check the keys. If the keys work properly in Sierra, it is unlikely that there is a hardware issue.

On each of the installations of Windows, can you run msinfo32 and post the value of BIOS Mode?

Has anyone resolved this? To me, this appears to be a certain bug in Sierra. I just upgraded a MBP 15 and an MBP 13 to Sierra. Both had working brightness buttons on El Capitan, and both have non-functional brightness buttons on Sierra.

dw

Yes, installed with Boot Camp when partitioning the disk and installing Windows 10.

Also, Apple Live Update updated the drivers. They now show up to date. Apple Live Update does not give an option for re-installing the drivers.

The MBP 13 is a 2013. It is running Sierra.

The MPB 15 was bought exactly 1 year ago, a few months before Apple released the new one with the soft function keys. It is also running Sierra.

The intensity buttons worked on both computers in El Capitan, running either El Capitan or WIndows (7 on the 13, 10 on the 15). The intensity buttons work on both computers running Sierra. The intensity buttons do not work on both computers running Windows (7 on the 13, 10 on the 15).

Thanks for the comments.

Tried SMC reset. I didn't see any indications that anything new was done.

Did the NVRAM reset, no change.

Since the slide bar in the Windows Display settings doesn't exist (anymore), I still have to believe this is a bug in the Sierra drivers.

Here's the Mac 15:

BIOS Version/Date Apple Inc. MBP114.88Z.0172.B09.1602151732, 2/15/2016

SMBIOS Version 2.7

BIOS Mode UEFI

Mac 13:

BIOS Version/Date Apple Inc. MBP81.88Z.0047.B3A.1706170652, 6/17/2017

SMBIOS Version 2.4

(no BIOS Mode exists in the system summary)

I like your idea of trying and external drive. It might take me some time to get that done since this is a holiday weekend and I'm out of town for almost 2 weeks. So there might be a really long delay.

Yes, I agree it's probably not a hardware issue. I still believe it's a driver issue.

Thanks!

I thought about this more since last night. This whole fiasco started because the upgrade from El Capitan to Sierra crashed and destroyed the boot sectors for OSX. I was told by Apple the crash happened because the computer shut down (by itself) and there is a disk format difference between the 2 versions preventing it from recovering from the crash.

I believe the problem is due to Sierra drivers installed when using Boot Camp on Sierra. And since both computers have the same problem, I assume it's Sierra and not anything else.

I'm guessing that if I boot OSX, the Windows drivers are not installed. I'm also guessing that if I boot El Capitan off an external drive, the Windows drivers also are not installed. So I'm not seeing how booting El Capitan off an external drive is going to narrow down the problem.

???

dw_apple wrote:

I thought about this more since last night. This whole fiasco started because the upgrade from El Capitan to Sierra crashed and destroyed the boot sectors for OSX. I was told by Apple the crash happened because the computer shut down (by itself) and there is a disk format difference between the 2 versions preventing it from recovering from the crash.

If the upgrade crashed, how did you correct the issue? The Apple explanation seems rather bizarre.

dw_apple wrote:

I believe the problem is due to Sierra drivers installed when using Boot Camp on Sierra. And since both computers have the same problem, I assume it's Sierra and not anything else.

What is the version of Sierra? Some 10.12.x releases of Sierra contain newer EFI firmware. If that was not applied or incorrectly applied, EFI device discovery can be compromised.

dw_apple wrote:

I'm guessing that if I boot OSX, the Windows drivers are not installed. I'm also guessing that if I boot El Capitan off an external drive, the Windows drivers also are not installed. So I'm not seeing how booting El Capitan off an external drive is going to narrow down the problem.

The common layer is firmware/hardware. None of the drivers interact with other OS's drivers. The difference is the EFI between El Capitan and Sierra. But it depends on the answer to my first question.

I started the Sierra download, WiFi, Mac plugged in. It took a long time, of course. I walked out of the room for a while near the end of the download, and when I returned the Mac was turned off. When I powered up, the status bar would run to about 95%, then the Mac would shut down again. This was repeatable.

But I was able to hold the Option key and boot into Windows. Windows worked just fine (even the brightness keys). I got busy at work, so I used Windows for some weeks before I had a chance to get back to OS X. I tried to repair the OS X partition. It would try 3 times then fail telling me it was not repairable. This was also repeatable. After many chats and phone calls with Apple, I was told that the OS X partition was not recoverable. It was an Apple employee at the store who told me that the file systems between El Capitan and Sierra were not compatible and they way it failed left the boot code unable to recover. Worse yet, in order to repair it I had to erase and rebuild my hard drive blowing away the Windows partition.

Still under warranty, I left my Mac at the local Apple store. They rebuilt the system with Sierra 10.12.6. I assume they erased everything as there was only a single partition on the disk when I got it back. So I then used Boot Camp to partition the disk, install the Windows drivers and install Windows 10. This is where I now have several problems I never had with El Capitan, screen brightness control just one of them. (The other problems yet unresolved are getting rid of that irritating start up noise ((the script file solution worked for a while, then stopped working)) and Windows constantly complaining about a disk not being inserted in the SD card slot.)

Thanks for the attention.

Dave

(I finally threw up my hands and set the SystemAudioVolume to zero. Eliminates the obnoxious startup noise, but also any other system sounds. At least I can reboot my Mac in OS X or Windows without waking up the neighbors.)

(Still need a solution to screen brightness and "no disk in drive" problems.)

dw_apple wrote:

I started the Sierra download, WiFi, Mac plugged in. It took a long time, of course. I walked out of the room for a while near the end of the download, and when I returned the Mac was turned off. When I powered up, the status bar would run to about 95%, then the Mac would shut down again. This was repeatable.

This may indicate a partial EFI upgrade.

But I was able to hold the Option key and boot into Windows. Windows worked just fine (even the brightness keys). I got busy at work, so I used Windows for some weeks before I had a chance to get back to OS X. I tried to repair the OS X partition. It would try 3 times then fail telling me it was not repairable. This was also repeatable. After many chats and phone calls with Apple, I was told that the OS X partition was not recoverable. It was an Apple employee at the store who told me that the file systems between El Capitan and Sierra were not compatible and they way it failed left the boot code unable to recover. Worse yet, in order to repair it I had to erase and rebuild my hard drive blowing away the Windows partition.

A restore from an El Capitan backup would have been an option. The file system description is not accurate. Core Storage and HFS+, both work. But this does not help you now.

dw_apple wrote:

Still under warranty, I left my Mac at the local Apple store. They rebuilt the system with Sierra 10.12.6. I assume they erased everything as there was only a single partition on the disk when I got it back. So I then used Boot Camp to partition the disk, install the Windows drivers and install Windows 10. This is where I now have several problems I never had with El Capitan, screen brightness control just one of them. (The other problems yet unresolved are getting rid of that irritating start up noise ((the script file solution worked for a while, then stopped working)) and Windows constantly complaining about a disk not being inserted in the SD card slot.)

There is a gap in information here. Did they replace the Logic Board because the firmware was corrupted and this was a faster method? What is the startup noise? The SD card issue just makes it a deeper mystery.

Are you willing to erase/install El Capitan?

Gee, I don't believe they opened the computer.

The startup "noise" is the chime when you boot, either in OS X or Windows.

The no disk in drive message is only in Windows, and only after installing Sierra.

Sigh.

Going over 100 degrees today. I have to escape the heat. Might not be back until tomorrow or possibly after the holiday.

Thanks,

Dave

dw_apple wrote:

Wow! Changed the system volume, rebooted, and now my screen is really dim. These drivers are really screwed.

You may want to look at the Registry and check the defaults. Post back when you are back.

I'm back. Should have stayed away. 109 yesterday, only 107 today. YUCK! I'm moving to Antarctica!

I booted in OS X. The screen was dim. I used the brightness buttons and they worked fine. I then re-booted in Windows and the screen was the same brightness, just fine. But the buttons do not work in Windows. So the problem hasn't changed (and appears to have nothing to do with changing the system message volume.

I'll have to research the registry. I have no idea where to look for screen defaults.

Thanks,

Dave