LCD brightness level automatically reset

Dear Experts and other user,
Started from yesterday, my T61 laptop LCD brightness level automatically reset to lower in everytime i started it. I needed to manually tune up the brightness level.
The laptop is firmly connected to the AC power. And i have did nothing under the Windows system. Is it any hardware issue or software configuration issue?
Many thanks with your attention and advise.
ED

My "energy saver" pref does NOT have the options for "Automatically reduce the brightness of the display before the display sleeps" item mentioned above. It has only the 4 following entries:
Wake Options:
-Wake when the modem detects a ring
-Wake for Ethernet network administrator access
Other Options:
-Allow power button to sleep the computer
-Restart automatically after a power failure
This option does show up in the help file and I am imagining that I either don't have the hardware to support it or it is geared for laptops.
I have tried using the terminal to issue a pmset command (logged in as root of course) to see if I could affect this behavior.
pmset -a lessbright 0
pmset -a halfdim 0
neither of them showed up in the file:
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
contents:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Custom Profile</key>
<dict>
<key>AC Power</key>
<dict>
<key>Automatic Restart On Power Loss</key>
<integer>0</integer>
<key>Disk Sleep Timer</key>
<integer>180</integer>
<key>Display Sleep Timer</key>
<integer>69</integer>
<key>Sleep On Power Button</key>
<integer>0</integer>
<key>System Sleep Timer</key>
<integer>69</integer>
<key>TTYSPreventSleep</key>
<integer>1</integer>
<key>Wake On AC Change</key>
<integer>0</integer>
<key>Wake On Clamshell Open</key>
<integer>1</integer>
<key>Wake On LAN</key>
<integer>0</integer>
<key>Wake On Modem Ring</key>
<integer>0</integer>
</dict>
</dict>
</dict>
</plist>

Similar Messages

Microphone level automatically resetting

I have set the microphone level on my iMac a number of times now and it keeps reverting back to the default level. I discovered this after my second or third video conference with iChatAV. The (same) person on the other end complained about my audio levels so I found that the level was reset in System Preferences. How do I get the microphone level to stay where I set it? Thanks.
cgreco16

This is a "feature" of iChat AV.
It has a built in Automatic Gain Control that resets your mic to between 67 and 80% whenever you open the preferences or un-mute it.
The only work-around that I am aware of is, since I use an external mixer, I set the input to be at the AGC level so I don't over drive it when the AGC does it's thing.

Laptop-mode / laptop-mode-tools lcd brightness issue

I have an issue with my lcd brightness config in laptop-mode tools
here is the brightness values
[venky@ARCHROCKS ~]$ cat /proc/acpi/video/VID/LCD/brightness
levels: 72 24 12 24 36 48 60 72 84 100
current: 72
[venky@ARCHROCKS ~]$
following is my lcd-bightness.conf file under /etc/laptop-mode/conf.d
# Configuration file for Laptop Mode Tools module lcd-brightness.
# For more information, consult the laptop-mode.conf(8) manual page.
# LCD brightness settings
# Using these settings, you can make laptop mode tools automatically adjust
# your LCD's brightness settings. The settings are extremely simple -- they
# only allow for the execution of a command, nothing more. The reason for this
# is that LCD brightness settings are very different between laptop vendors.
# Suggestions for commands:
# * If your system has the file "/proc/acpi/video/VID/LCD/brightness" (VID may
# be VID1 or similar), use this file as BRIGHTNESS_OUTPUT, and use
# the command "echo <value>". The possible values can be listed using the
# command:
# cat /proc/acpi/video/VID/LCD/brightness
# * If you have a file /sys/class/backlight/.../brightness, then you can use
# that file as BRIGHTNESS_OUTPUT, and the command "echo <value>".
# As far as I understand it the values are between 0 and
# the value contained in the file /sys/class/backlight/.../max_brightness.
# * For Toshiba laptops, use the command "toshset" with the -lcd or -inten
# command. Read the toshset(1) manual page for more information on the
# parameters for this command. If you use this command, set
# BRIGHTNESS_OUTPUT to "/dev/null".
# IMPORTANT: In versions 1.36 and earlier, these settings were included in the
# main laptop-mode.conf configuration file. If they are still present, they
# overrule the settings in this file. To fix this, simply delete the settings
# from the main config file.
# Should laptop mode tools control LCD brightness?
CONTROL_BRIGHTNESS=1
# Commands to execute to set the brightness on your LCD
BATT_BRIGHTNESS_COMMAND="echo 24"
LM_AC_BRIGHTNESS_COMMAND="echo 100"
NOLM_AC_BRIGHTNESS_COMMAND="echo 72"
BRIGHTNESS_OUTPUT="/proc/acpi/video/VID/LCD/brightness"
so basically while in AC power i want full brightness when on battery i want one notch more than the minimum brightness and when laptop-mode is not running i want 2 notches less than maximum brightness.
the battery mode works fine when i unplug the computer but when i replug the AC power it goes to 72 instead of 100. I mean laptop mode is running coz when I remove ac power it goes to 24 again.
Am I doing something wrong?

When you plug in AC power, laptop-mode probably turns down, so LCD brightness is set to 72. It depends on if you have set in /etc/laptop-mode/laptop-mode.conf ENABLE_LAPTOP_MODE_ON_AC to 0 or 1.

LCD brightness issue

I've installed archlinux on my laptop, everything works well except the brightness control.
The screen originally has 11 brightness levels, but when I either press Fn+F6/F7 key or use gnome-power-manager to adjust brightness, it always skips a level.
/proc/acpi/video/VGA/LCD/brightness
levels: 100 60 20 28 36 44 52 60 68 76 84 92 100
current: 100
I can only get level 20 36 52 68 84 and 100
The problem also exists in console mode.
I tried adding video module to blacklist, then brightness cannot be adjusted at all.
However, I never get this problem in openSUSE, all 11 levels are available.
Could anyone help me? Thanks!:|

http://forums.nvidia.com/index.php?show … t&p=386303
Hmmm...I found this on the nvidia forums:
I have a Samsung R700 laptop and my brightness stopped working after installing the restricted drivers. This is how I fixed it.
Press Ctrl-Alt-F1 to get a virtual console. Once you are in this console I think different video drivers are active so the following worked for me to adjust brightness.
Logged in and ran the following command:
echo -n 70 > /proc/acpi/video/NVID/LCD/brightness
then logged out and pressed Ctrl-Alt-F7 to go back to X
It's possible your brightness key on your laptop may work straight after you press ctrl-alt-f1 and you won't have to login and do the acpi stuff.
Also I have a startup script to set my brightness to a fixed value before X starts. It's not ideal but it's the only solution I could find that worked for me until the drivers are fixed!
Hope this helps.
Last edited by kclive18 (2008-07-08 11:19:25)

Brightness levels reset to default on restart

I'm using iBooks & find it frustrating that if I change the brightness level, the new level is not remembered & find it reverts to the default level each time I re-open I-books. Perhaps this issue could be rectified at a future version revision?

Try completely closing out of iBooks: from the Home screen double tap the Home button, once the multitask bar appears hold down on the iBooks icon until it starts to jiggle, press the red icon in the corner to close out of iBooks. Now restart the iPad and see if this might help resolve the brightness issue.
Alternatively instead of a restart you could perform a Reset once you close iBooks. Reset: hold down the Home and Sleep/Wake button at the same time for ~10sec, ignore the Slide to Power Off, the iPad will then Reset, Note: No data is lost during a Reset.
if the problem continues you might need to delete iBooks and then redownload it from the App Store. if none of the suggestions provided dont help resolve the issue then I suggest leaving feedback here: http://www.apple.com/feedback/

Brightness issue-automatic dimming

Hi everyone,
I just bought my 20' inch iMac 2 months ago. I've done some updates before but the last time that I did it was like 2 or 3 weeks ago.
I used to keep my brightness level at the maximum. I don't know why but suddenly and randomly my iMac monitor's brightness would automatically become dim all the way down now. I tried adjusting the brightness level in System Preferences > Display but fails. Every time I drag the level of brightness bar back to the right, it'll then automatically go down. Pressing the F2 key on the keyboard is also useless, there is simply no response. The only way to be able to keep the brightness level bar at the far right hand side (i.e. maximum) is to change the display resolution to a lower one and then bring it back up again to the highest. This is quite annoying.
It happens randomly. So sometimes I've been using the iMac for like a couple hours and all is fine. Sometimes this happens like 5 mins after I start it up. I really don't know what to do. Please could anyone kindly help?
Thanks a lot! I truly appreciate.

Mine does the exact opposite. I put my brightness at the lowest setting to keep the computer from getting so hot, and after the display goes to sleep, it is back at full brightness. I lower it either in the preferences or using the keystrokes. Still goes back to maximum.

Strobing Screen on MBA (all brightness levels)

I seem to have gotten a Mac with all of the above.
Losing WiFi connection, and not being able to turn WiFi back on.
Screen randomly going black after sleep
And now the new addition to the list:
Screen flickering at approx 25 frames per second on all brightness levels on both battery and. Restarting randomly fixes the problem, randomly does nothing. I have reset the SMC / PRAM. Seems this otherwise beautiful baby is going back .
Add yourself to the thread if you're experiencing the strobing effect.

I have the same strobbing or pulsing back light problem. I really regret getting this new MBA. The 2010 model had none of these issues. My laptop doesn't wake from sleep randomly, when it does it takes forever to actually resume and now this black screen with the flashing backlight. Apple needs to address all these issues ASAP or I'm going to ask to return this thing for a refund!

New iMac brightness level keeps changing (auto adjust NOT checked)

Just got a new 27 inch iMac and keep on having to change the brightness level back to the brightness I prefer.
I do not have auto adjust checked, I put the brightness slider up to the level I like and after a while the brightness dims to what seems like the default level as its always down to the same spot on the slider...what gives? i just want it to stay where I want it...
Help.

I have same problem, of autobrightness being unchecked and my brightness going from full to about 3/4 bright
all by itself. I had that problem, then flickering of my screen also was taking place. I didn't bring my unit into Apple
because this autobrightness thing plus flickering would not happen on command,, and I wouldn't be able to show them properly. Well , finally my left side of the screen dimmed,, and that was the go ahead to bring it in to them
to show the left side of screen. I also told them about the flickering,, and the autobrightness, which I figured played a role into the final left side dimming. They replaced the backlight and the display LCD on warranty.
I have had it for about 5 days. The screen is equally lit (as should be), however, I discovered that my same old
problem of autobrightness, is slipping back to 3/4. So most of you have autobrightness problem in a sort of different way. I set mine to "torch" because my downstairs bedroom is dim (with one overhead light), but sometimes, just plain dark,, so I want to sometimes keep it at torch,, however, it still slips back. You would
almost think that if my surronding was dim or dark, that it would stay on torch if the autobrightness was really working properly. Go figure. I just tried SMC a short while ago,, I had tried, before my repair doing PRAM and the other one (I think VRAM). I also will unhook my second monitor to see if that is having an impact on things.
Do any of you in this post have a second monitor attached,, and have you tried unhooking it to see if the problem
is resolved?

Brightness levels decreased after installing 10.6.2

My computer came with Snow Leopard (it's the 13" Macbook Pro) and after installing the upgrade from 10.6.1 to 10.6.2 I noticed that the brightness decreased dramatically. I don't think it has anything to do with gamma as I tried to adjust that and it didn't really make that big a difference. I have now increased the brightness but I still think there might be something wrong with my laptop because I don't know if the update could decrease the brightness levels as they were the default levels, I hadn't changed them... It would seem strange somehow... I did install the update when I didn't have the computer connected to a power source, could that have caused this? Could installing the update again help? Or could I uninstall it somehow? This is my first Mac so I'm rather clueless about everything...

blaeblae wrote:
My computer came with Snow Leopard (it's the 13" Macbook Pro) and after installing the upgrade from 10.6.1 to 10.6.2 I noticed that the brightness decreased dramatically. I don't think it has anything to do with gamma as I tried to adjust that and it didn't really make that big a difference. I have now increased the brightness but I still think there might be something wrong with my laptop because I don't know if the update could decrease the brightness levels as they were the default levels, I hadn't changed them... It would seem strange somehow... I did install the update when I didn't have the computer connected to a power source, could that have caused this?
yes, that was most likely it. and a bad idea it was on your part. never do that again. if the computer runs out of power in the middle of an update this can brick your system and require a reinstall.
Could installing the update again help? Or could I uninstall it somehow? This is my first Mac so I'm rather clueless about everything...
you don't need to do anything. the brightness was reduced automatically during the update to conserve energy.

Screen goes back to lowest brightness level after wakeup

Hello All,
My late 2002 Titanium Powerbook screen sometimes goes to the lowest brightness level after wakeup when the lid has been closed. I manually have to reset the level again. Does anyone know why the level is not staying to my original setting? Do you think there's a corruption in the wakeup mode function? Just a hunch, though. Any input is much appreciated. Have a great day.
Jack
iMac G5 20, 2 GHz, 1.5 GB RAM Mac OS X (10.4.8) Powerbook 15" Titanium (late 2002) 1 gHz, 1 gig RAM, 60 gig HD, OS X 10.4.8

Hi TJK,
I just did a permission repair with disk utility to eliminate any other issues. I'll create a new user and give your suggestion a try. It makes sense since I recently got this machine used from another owner. I've nothing to lose, I suppose.
While I'm here, would a clean install eliminate the issue I'm having? I'm not too excited about having his name on my Home folder permanently, anyway. I've no problem doing a clean install, and I've got the original install disks.
Best regards,
Jack
iMac G5 20, 2 GHz, 1.5 GB RAM Mac OS X (10.4.8) Powerbook 15" Titanium (late 2002) 1 gHz, 1 gig RAM, 60 gig HD, OS X 10.4.8

Spasming brightness level

Every now and then, this thing happens on my W701ds, where I open the lid (I have it set so that it does nothing on closing the lid...so it's not coming out of sleep or anything) and the screen brightness level starts twitching back and forth between two settings (like between 10 and 11). The only way to get it to stop, is to hold down one of the brightness Fn keys to push the level all the way to the min or max.
Has anyone else seen this? I searched and couldn't find anything, but maybe it's been described differently. It's fairly spectacular, so I have to imagine someone else has posted about it.
I'm not even sure what to target as being responsible for this. It does seem like it normally adjusts its brightness to the abient light level, I assume using the same sensor as for color calibration. Is it HueyPro that does this or some other system component?
This may be unrelated, but occasionally when I open the lid it comes up with an odd colored cast to it for a second or so, as if it is adjusting the colors, though I didn't think that was supposed to be happening automatically.
If anyone can give me any clues about how this stuff works / is supposed to work, I'd appreciate it.
Thanks,
Eric

This also happens without lifting the lid...if the monitor gets shutoff to save power if I have not touched it in a little while, it sometimes goes into spasm mode when I move the mouse and it turns the monitor back on. Which brings me to theorize a cause:
I suspect that the power manager which adjust the brightness level according to your power scheme (such as to turn the monitor on or off or adjust brightness differently for powered vs battery) ends up "fighting" with the component (HueyPro, I believe) that is changing the brightness level for room light compensation. I think it happens when the room light level has changed between when powermanager turned off the monitor, and when it turned it back on.
If so, its not clear which of these components is at fault or if it is something at a deeper system level that should be coordinating between them.

Ergonomic Brightness Level for Late 2009 iMac 27" i7

Hi. Apple seems to default the brightness level to full when you buy it and I've read some iMacs flicker unless it's brightness level is set to full bright. For the late iMac 2009 27" i7, what's do experts say about ergonomic brightness level for this Mac, for LED LCDs? I won't be doing professional printing by the way. Thank you in advance.
Gbu

I set mine to something between 50-70% of the max depending on the time of day and the amount of sunshine.
No buzzing at all.
Stefan

Does SAP increase SM50 ... - trace level automatically?

Hi experts,
Does SAP increase SM50 ... -> trace level automatically? I find file system is full in application server from time to time and I find trace level increases to 2 from default: 1. Why? How do I prevent from reoccurring?

Hello
These files are work process trace files, this has nothing to do with the system log.
You can restrict these file growth using instance parameter rdisp/TRACE_LOGGING as stated in the here under note.
Check also the value of instance parameter rdisp/TRACE as stated in note 112 - Trace and error information in the "dev_" files
Regards
573800 - Reasons for trace files increasing in size
How can I prevent trace files that are increasing in size from filling the hard disk and causing the system to shut down?
- Reset the trace files (as described as Section 1 of note 532918).
- Set the "rdisp/TRACE_LOGGING = on, 10 m" profile parameter

[SOLVED] Setting LCD brightness in terminal

I'm trying to set LCD brightness in script. But unfortunately the desired command do not work.
I've grepped my VGA card number
01:05.0 VGA compatible controller: ATI Technologies Inc RS780M/RS780MN [Radeon HD 3200 Graphics]
"setpci -s 01:05.0 F4.B=F0" do not change the brightness whatever value I use.
My pc is a thinkpad laptop. If there is any workaround?
Last edited by tasty_minerals (2011-10-12 20:13:37)

roygbiv wrote:
I used this script binded with two keys:
#!/bin/bash
file="/sys/class/backlight/acpi_video0/brightness"
level=$(cat $file)
if [[ "$#" -eq 0 ]]; then
cat $file
elif [[ "$1" = "-" ]]; then
echo $(( level - 1 )) > $file
elif [[ "$1" = "+" ]]; then
echo $(( level + 1 )) > $file
fi
By adding the location of the script to root's $PATH, i.e $HOME/myscripts, it can be run with sudo. It accepts '+' and '-', but it can easily be changed to handle brightness [0-24] values I guess.
thanks again, will try it out

Latest Update breaks brightness level in iMac

Everytime I restart, the brightness level jacks up to 100% The effective brightness I have calibrated for is on 0% This started happening directly after the latest 10.5 update. Its annoying to reset it everytime I restart.
I have a 17" 2006 imac. The first intel one.

I would try both a PRAM and an SMC reset.
PRAM
1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.>
SMC
1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
2. Unplug all cables from the computer, including the power cord and any display cables.
3. Wait at least 15 seconds.
4. Plug the power cord back in, making sure the power button is not being pressed at the time. Then reconnect your keyboard and mouse to the computer.
5. Press the power button on the back to start up your computer.
Dah•veed

LCD brightness level automatically reset

Similar Messages

Maybe you are looking for