Ask Max: G4 PowerBook Settings Are Resetting To Default
I use a PowerBook G4 running OS X 10.4.11
I periodically find that some of my settings unpredictably change back to a default setting that is NOT to my liking. Two examples:
In the Display Preferences control panel, I like to keep my display set almost at the brightest setting. The "automatically adjust brightness" box is not checked.
Yet sometimes when I start up my Mac, after squinting at the faint screen for a while I realize that the display has returned to a much dimmer setting. I now keep the display settings icon in the top menu bar so I do not have to navigate to it each time I want to reset my display to a brighter setting.
Another issue is the view setting in my email inbox. I like to have certain columns visible, but sometimes I find that the display has reverted to the stock minimalist view and I must reselect the columns I would like to have displayed.
Any idea what's going on, and how I can make it stop?
The problem with the dimming screen could be caused by a few "features" of the Apple laptop design. The first possible cause would be the brightness keys being inadvertently pressed. On all the G4 PowerBooks and later laptops, Apple has included brightness keys as a sub-feature of the F1-F12 keys The icons for raising the brightness is a big sun image and to lower the brightness is a key with a little sun image. The function keys that these are associated with the icons vary from model to model. Depending on the settings your apple computer has, you may need to hold down the Function shift key [FN] to activate the special function of those Brightness keys. It is possible that when hitting a nearby key your finger is also connecting with the brightness keys. I reverse the special function of those keys In the Keyboard & Mouse System Preferences to avoid those kind of accidental changes.
The second possibility you have already ruled out but it is often the problem for other users. For others the dimming could be due to Ambient Light sensors. Many newer Apple computers with built-in displays have sensors in them that detect when the room is dark. The computer can then dim the screen when the lights are lowered, so that the user’s eyes are not blinded by the screen. You can turn off this feature in the Display System Preferences. This feature is set by a checkbox, labeled "Automatically adjust brightness as ambient light changes."
The third culprit affects desktop Macs more than Apple laptops. Desktop Macs have a small battery to retain sound and brightness settings, among other things. A failing battery in a desktop could cause these settings to reset to defaults, perhaps a failing battery in you laptop or other power system problem could cause a similar effect. Try resetting the PMU and PRAM via these instructions and see if your settings are retained after restart. http://support.apple.com/kb/HT1431
The issue with Apple Mail changing column listings is a bit trickier. I have personally experienced this problem but not as frequently as you have. It has yet to occur in OS X 10.5 Mail. This seems to be an issue with the 10.4 Apple Mail plist file, and the way it writes those column changes during operation. To my knowledge there is not a fix, other than moving to 10.5, but you can always try some general disk maintenance, like repair disk permissions, to see if that fixes it.
Hope that helps,