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Philippe M Level 1 (0 points)
After updating BootCamp Services from 2.02 to 2.1, I have to face an issue with brightness of my screen.

BootCamp 2.1 sets the brightness to the minimum value (very difficult to work with) and I didn't find any option (in windows) to revert brightness to the initial value (max). Brightness +/- function keys (F1/F2 alu keyboard) do not operate.

When switching to MacOSX, the display brightness is also at the minimum value but I can revert it back to the max value. Then switching back to Windows... brightness is at the max value during the boot process and then is reduced at the minimum as soon as the boot camp services are loaded !...

I removed BootCamp Services 2.1 and reinstalled BootCamp Services 2.02... no brightness issue. Then updated again to 2.1 and got that problem back.

Anyone having to face that issue?

My config:
MacPro (Early 2008)
Apple Cinema HD Display (through Apple ADC-DVI adaptor)
Windows Vista Ultimate 64 bits

Thanks in advance for your feedback

Mac OS X (10.5)
  • Moonlight Mac Level 1 (105 points)
    Oddly enough, I'm seeing somewhat the opposite problem on a MacBook Pro with the Bootcamp 2.1 drivers.

    In XP, the brightness is always 100%. I can use the keyboard to change it to less than 100%, but then a second later it returns to 100%. I didn't have this problem with 2.0.

    Can you change bightness with the Brightness tab in the bootcamp control panel?
  • The hatter Level 9 (60,930 points)
    "After rebooting in Bootcamp Windows XP, I installed the Bootcamp Update 2.1. After a Restart, back in Windows XP, I had a Screen Resolution of 640x480 Pixel an 16 Colors. And whatever I tried, it was impossible to change that."

  • Moonlight Mac Level 1 (105 points)
    I don't believe this is a video card driver related issue. It appears to be a bootcamp issue controlling the brightness of displays.
  • Philippe M Level 1 (0 points)
    Hello Moonlight Mac,

    I do have a MacPro, and in that case, there is no Brightness tab in the BootCamp preferences (not like your MacBookPro).

    Thanks anyway for the idea.
  • Moonlight Mac Level 1 (105 points)
    Ahh... I figured that since the brightness was controllable over USB, that bootcamp was changing the brightness of the display, especially since you mentioned that reinstalling BC 2.0 brought it back to normal.

    Do you think it is a brightness issue, or a driver issue? Do the brightness controls on the side of the display work? Can you adjust it with the nVidia control panel, it has all kinds of brightness and gamma features.

    OK... how about this:

    Is your cinema display USB cable connected? If it is, try unplugging the USB cable. Boot into Mac, set brightness to full (may be an unnecessary step) pull the USB cable, then boot into PC... it shouldn't be able to dim it unless it is talking to it via USB. At least that is my guess. I use an older cinema display on a PC, and it knows nothing about the backlight... and therefore doesn't change the brightness.
  • Moonlight Mac Level 1 (105 points)
    Oops... you mentioned ADC to DVI adapter... so your display doesn't have brightness controls on it.
  • TheBoyKen Level 1 (0 points)
    I've got a 2007 8 x 3.0GHz Mac Pro with a 23" Apple Cinema Display going via an Apple ADC->DVI adaptor.

    With the factory fitted ATI 1900XT and Boot Camp 2.0 / XP SP2, everything was fine (except the ATI graphics card either overheating or attempting levitation every once in a while, but that's par for the course).

    Upgrading to Boot Camp 2.1 (without doing XP SP3), and suddenly I'm getting the same dim monitor as the original poster. Installing "real" ATI drivers and the ATI CCC tool didn't do anything (there were brightness controls in the drivers, but they made the picture awful, unlike the keyboard-based brightness mac users are used to). Installing XP SP 3 made no difference.

    So I re-installed everything (in terms of Boot Camp / XP SP2). Back in Boot Camp 2.0, it's rosy again. Install Boot Camp 2.1 (without any Windows updates at all over and above XP SP2) and the problem is back.

    Re-installed all the Boot Camp / Windows stuff (each time reformatting by the way), this time having swapped the ATI 1900XT for an Apple Nvidia 8800GT. Although the mac no longer attempts vertical take off, and although I can now hear a pin drop, the picture issue remains: Boot Camp 2.1 dims the monitor, and nothing (in XP) can fix it. So it's not a specific graphics card issue, as it's happening under ATI and Nvidia cards.

    As the original poster said, you can go back into Mac OS X, use the keyboard (or brightness settings in the Displays System Preference), and you're fine in Mac OS X. But go back into XP and it goes dim again. Interestingly it's not immediately dim in XP, it happens when the boot camp system tray icon (those things down by the clock in XP) loads... up until that point the monitor is fully bright in XP, assuming you'd just previously fixed it in Mac OS X prior to booting.

    The solution for me was along the lines of what Moonlight Mac was suggesting: go into Mac OS X with everything plugged in normally, chuck the brightness up to your preferred amount, then remove the USB cable belonging to the DVI->ADC adaptor (which for me was going straight into the back of the mac). This prevents the mac pro (or you) from being able to adjust the monitor's brightness. Now boot into XP and you can actually see the desktop.

    Aargh it's horrible, turn the lights back off!

    Although it provides a makeshift fix, the disadvantages are:

    [1] You still can't adjust the brightness in XP, you have to go Mac OS X -> plug cable in -> adjust brightness -> remove cable -> reboot into XP. For me I want it at full brightness all the time, so this limit doesn't bother me.

    [2] You're a USB socket down on the deal (the ADC monitor & ADC->DVI adaptor give you 2 sockets and take up 1 (in the mac), whereas now you only have that 1 (in your mac).

    So it looks like an issue between Boot Camp 2.1, and the ADC->DVI adaptor (or the Apple Cinema Display). The original poster suggested re-installing the Boot Camp 2.0 drivers, but I didn't attempt this so can't say if rewinding to Boot Camp 2.0 (rather than reinstalling, which was the path I took) works in my config. The reason I didn't want to stay on Boot Camp 2.0 was because 2.1 made the 802.11n Airport network actually usable under XP (fine in Mac OS X of course), and that was more important to me than the 1x USB socket that I have to sacrifice using my fix.

    Hope this helps,
    p.s. very glad to find this post as Google & Apple Support searches hadn't been turning up anything. I thought I was going mad
  • Moonlight Mac Level 1 (105 points)
    OK, this is a TOTAL shot in the dark, but what happens if you open the Device Manager, then from the view menu select "show hidden devices"

    Under the System devices category, try disabling "Apple panel backlight"

    After that, reboot into osx and make sure display is operating normally, then boot into windows and see if it stays bright (with the USB pigtail from the DVI to ADC adapter connected the whole time.)

    If that doesn't work, there has to be a device or service that can be disabled to prevent the backlight from getting dimmed.
  • Ian Aberle Level 1 (45 points)
    Philippe -

    I was having the same issue as yourself, but with Windows XP.

    I think I've found a solution. WinACD is a Sourceforge project to add Apple Cinema Display HID driver and control panel for Windows XP.

    I installed it and restarted. It added back the activity to the brightness control button and added brightness control to the display settings. If you go to "Advanced" under the display settings, there will be a tab for "Apple Controls." Using that tab, you can set the brightness for the monitor, plus add keyboard controls for the brightness setting.

    You can download it here

    Hope this helps.
  • Daniel MAZE Level 1 (0 points)

    I had the problem too, but you resolve it. It works fine now.

    Thanks Ian

  • Ian Aberle Level 1 (45 points)
    Thanks Daniel.

    Hopefully Philippe has also found this helpful or solved and mark it as so.
  • mikraz22 Level 1 (0 points)
    Indeed. Instlling that WINACD fixed the dimming issuethat boot camp update 2.1 seemed to create. Installing he WINACD application in the advanced menu is genius. Thanks for solving this issue.
  • Will Tschumy Level 1 (0 points)
    WINACD doesn't work in 64bit Vista - any other workarounds?
  • Adam Prall Level 1 (50 points)
    Same here, problem with 64-bit Vista. Ended up installing a separate 32-bit Vista partition on this computer in order to run the numerous programs/drivers that won't run in 64-bit.
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