How to bring brightness control slider back in display Preferences if its missing?

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sunny_1991 Author

Level 1

17 points

How to bring brightness control slider back in display Preferences if its missing?

Hi,

I am using MacBook Pro(Mid 2010) 15". I have Mac OS X Lion(10.7.3). Before a week i was able to control brightness of my LCD display (i.e., 15" screen, not any other external Monitor) through Brightness keys from Keyboard, but it stopped working before 5-6 days. Then i tried to restart my laptop many times, nut it didn't helped. After a while i search through many discussion and forums over internet for finding my solution but it didn't help. Then i read somewhere that use slider control in display preferences. So, i went to display preferences, then i saw that there is no slider control in display preferences. Now i don't know what to do. So plz guys help me if you know any solution to this problem.

I have attached the image of my Display Preferences for getting you an idea what i am saying. And i Think if the slider comes back then keyboard keys will also get working automatically.

MacBook Pro, Mac OS X (10.7)

Posted on Apr 29, 2012 9:06 AM

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Answer 1

Best reply

CT

Level 7

23,987 points

Apr 29, 2012 9:21 AM in response to sunny_1991

One harmless thing to try is to reset the NVRAM:

Resetting your Mac's PRAM and NVRAM

charlie

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Answer 2

Linc Davis

Level 10

209,547 points

Apr 29, 2012 10:11 AM in response to sunny_1991

If the monitor has a USB cable, plug it in.

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Answer 3

rudy_

Level 1

0 points

Apr 30, 2012 11:30 PM in response to sunny_1991

Hey sunny_1991.

The exact same thing has happened to me.

I am running a 27" Thunderbolt display off of a Mid-2011 MacBook Air.

Suddenly, last week, my brightness control keys on my external keyboard stopped affecting the brightness of the Thunderbolt display. The brightness keys on the MacBook Air, though, still affect the brightness of the laptop's screen.

I went into the Displays preference pane, and sure enough, the brightness slider has disappeared.

Have you been able to resolve this? (zapping PRAM, etc doesn't work.)

I'm wondering if this is a glitch that came with 10.7.3...

Anyone have any ideas? I have no way, now, to control the brightness of my Thunderbolt display. It is EXTREMELY frustrating.

rudy

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Answer 4

rudy_

Level 1

0 points

Apr 30, 2012 11:43 PM in response to rudy_

UPDATE:

This resolved the issue:

http://download.info.apple.com/Apple_Hardware_Test/EDID_Reset_Tool.dmg

(this is an Apple tool to reset the EDID after the LCD panel or logic board is replaced. My monitor, though, was never taken in for repair. The brightness controls went kablooey just sitting on my desk.)

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Answer 5

sunny_1991 Author

Level 1

17 points

May 1, 2012 12:48 AM in response to CT

Thanks CT, I tried for resetting NVRAM. and it worked perfectly fyn. Brightness controls are back, and slider also. So Thanks A Lot for the help.

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Answer 6

sunny_1991 Author

Level 1

17 points

May 1, 2012 12:50 AM in response to Linc Davis

Linc Davis.

Problem was in my internal Display. So no USB cable.

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Answer 7

sunny_1991 Author

Level 1

17 points

May 1, 2012 12:53 AM in response to rudy_

heyy rudy

There was problem in my internal display, with internal keyboard. So i think problem was little bit different. but anyways thanks for that tool (I have downloaded it.). In future, if i replace or anything happens in h/w. i will try to use that tool. Thanks.

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