halfdim setting ignored
 

I have a long-standing issue with the screen of my PowerBook dimming on idle while on power from its adapter in spite of settings to the contrary in Energy Saver or the corresponding value for the pmset halfdim argument. I'm aware of similar threads here on the forums but my symptoms are somewhat different, so I've started a new thread.

As a workaround, I've been checking and unchecking again "Automatically reduce brightness [...]" in Energy Saver every time I notice it. This does the trick, but I shouldn't have to do this and I'm asking for help from anybody reading this who might know what to do.

It appears that there are a few circumstances that may instigate the problem:

• Reverting to adapter power after running on battery
• Coming out of sleep
• Removing or reattaching an external display
• Changing network locations

I've tried to isolate those events through testing (because in normal use I usually do two or more of those things in tandem), but there is no change.

Troubleshooting details:

• The problem is persistent across user accounts regardless of admin or regular privileges, and including brand-new clean accounts.
• The problem has survived reboots, permission fixes, cache cleanings, and an nvram reset.

System info:

• 17" PowerBook G4 1.5GHz, circa mid-2004
• Now running 10.4.8
• Problem began a while ago; perhaps with one of the early 10.4 point releases.
• output of pmset -g:

Lastly (and this seems very peculiar to me, but maybe it's nothing): I can not find any property list file for Energy Saver preferences anywhere I would expect it to be on my machine. Not in /Library/Preferences, ~/Library/Preferences or ~/Library/Preferences/ByHost. I've looked for "EnergySaver," "Power," etc. in the file name.

That's really all the information I can provide except perhaps that my "higher-level purpose" is to stop the screen from dimming when I don't want it to (ha ha).

Any help on this is appreciated. Thanks in advance.

I believe the file you are looking for is com.apple.powermanagement.plist (If I remember correctly...)

But anyhoo welcome to the club... This has annoyed me with my powerbook since about a month after I bought it back in November of last year.

Anyhoo I did write a one line applescript to fix this that I just saved as an application and left on my desktop to use whenever it happens. I've attached the code below. Just put in your password where it says to and you are good to go.

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do shell script "sudo pmset halfdim 0" password "insert password here" with administrator privileges
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The halfdim "feature" is just idiotic.... What benefit is a halfdimmed screen? Turn the freakin' screen off...or leave it on...not some zombie in between state.

Yes, that's it. Thanks. It lives in /Library/Preferences/System\ Configuration. That might explain why I didn't find it. I've examined the contents: The AC Power "section" matches what I posted above from pmset -g output and it changes as expected when I use system preferences to toggle halfdim, so this isn't the source of the problem.

Thanks for the tip -- it's definitely quicker than running to system preferences. But I'm a little skeptical as to its effectiveness: halfdim is already at 0. Maybe "sudo pmset halfdim 1; sudo pmset halfdim 0" to echo the act of checking and unchecking the setting? Anyway, I'll give something like either of those a shot the next time I notice it as a new workaround.

I'm not sure I agree with that: I find it really useful when running on battery power. I just wish turning it off would stick when on AC.

^^^Trust me the applescript works. Something is corrupted and the computer is ignoring your preferences file (from my experience). I've looked at my preferences when it has happened before and the setting is exactly how I left it.

The above applescript just forces it to accept the setting (or completely overwrites it or something) Don't ask me. I just know it works...and works for others I've given it to as well. If my screen starts halfdimming I just click on it...and the problem goes away...until it comes back days later and several system sleeps later.