automatic screen dimming in 10.3.8
 

hi,

am i going mad, or has the screen settings for automatic dimming on my 15" powerbook become overly sensitive all the sudden? (well after updating to 10.3.8)...

i'm in a bright office, and if i wave my left hand over the top of the speaker grill, it will dim the screen... the problem is when anyone walks past, the screen dims also!

is there anyway of deactivating this for just when i have AC plugged in? i know i can just turn it off altogether, but it's quiet useful when i'm on batteries.

You should be able to set up separate profiles for ac adpater and Battery use. If you go to energy save pref pane you should see a settings for power adapetr and battery power bar. I have mine set for two different things. My Optimze Energy settings is set to custom. Then you should be able to set different values based on Power adapter and battery.

I just realized these settings are for sleep and such, although I son't see the same issue you are seeing with yours on my 17" PB. I am not sure how this effects dimming but I don't have a problem in my bright office.

I've seen the same thing happen on my 15 inch too, but it doesn't always seem to happen... As he said, looks like the sensor has become overly sensitive...

So the 15" only has one light sensor? The 17 has two. I've noticed if I leave something sitting over one of them (like a CD), then with just one active it gets very sensitive. If the 15" has two sensors, maybe you're covering one somehow?

well, the light sensor appears to be near the top of the speaker grill; which is where i rest my hand sometimes when i type... :)

but the point is that this never used to happen before i upgraded to 10.3.8.

I personally have not had this problem on my 15" Pb, but macfixit.com mentioned other reports of this problem today.

Any chance that the sensor has some dirt on it? Based on what was said about the 17" PB, anything that partially blocks the sensor makes the system oversensitive.

Just so you know that you're not imagining things, I've seen the same thing happen to my 15" Powerbook after updating to 10.3.8. It is inconsistant. So, when it starts acting up I just turn the autosetting for brightness off.

according to macfixit.com today there is a fair amount of people seeing this problem. The apparent fix is to turn off the automatic screen brightness feature.

it's not really a fix tho' is it? :(

i'm surprised that you can't associate the dimmer with the Energy Saver settings.

I agree that it isn't a fix...I too find it odd that you cannot link it to energy saver. I personally don't use the auto dim. I just use the brigtness keys. I am rarely using my pb in a dark room.

God, this is nuts. I lifted my left hand to adjust the angle of the screen, some three inches above the speaker, and the screen started dimming! And stopped when I moved my hand back to the keyboard. This definitely started with 10.3.8. I bet some engineer thought he was "improving the response time" or something.

I wonder if a clue exists in the logs. In my Console log and System log, there are unusually frequent references to:
kernel: AppleLMUController: setLEDBrightness - Brightness level requested at: 0x0000018A

over and over again. I watch the logs, so I know the frequency is a recent and unusual thing. Or is setLEDBrightness for the keyboard backlighting?
:confused:

If you are getting dimming when only covering one sensor, then the other sensor is probably dead. There is a sensor on both sides of the keyboard. (they are not directly across from eachother, one of them is closer to the LCD than the other) I observe the same message in console when I cover both sensors on this 15", but if the room is bright I have to cover both sensors very thoroughly to fool them.

But why would all these powerbooks sensors suddenly fail at the same time? and coincidentally with the installation of 10.3.8?

Somehow I think this seems to be a software related bug rather than a hardware failure. But then not all powerbooks have the failure..

iNemo has asked the million dollar question. Nobody complained about this before 10.3.8. I guess we'll just have to see if it's fixed in the upcoming 10.3.9 update (rumor).

Might just be 10.3.8.1 to fix the powerbook sensor code though... ;)

OK folks, at least two web sites are reporting that the problem is with the new version of the AppleLMUController kext. If you dig out the old one with Pacifist it will work right again. I haven't tried it yet.
Fix for wacky brightness