[xMetal]

I did some web searches and could not figure out why this started happening.

My PB 17" keyboard backlight just will not turn on. I've ensured the preference is turned on, and if I hit F8, F9, or F10 I just get this:



I've had powerbooks for a long time, the mac for even longer, and can usually troubleshoot most anything, but I can't figure out why this won't work. I'm not sure when this behavior started, but I don't think I've got anything installed that would conflict. I'm running 10.4.1 with all the proper updates.

Any ideas?

[Squelch11]

Is there too much ambient light? If it's too light in the room you're in, the keyboard backlight won't come on. I freaked out when I first got my 17" thinking the backlight was broken too. But if you go into a room that's not very bright, it should come on.

If you can't get to a darker room, you can cover the speaker gratings on both sides of the keyboard, and the backlight should come on. Then you can play with the brightness...

Hope this helps.

[analogika]

Squelch has it: the F8-F10 buttons will only work if the backlight is on, which it only is if the ambient light sensors under the speaker grilles say that it's dark.

[xMetal]

I've had this PB for years (ordered the day they were announced) and it's always been fine. This problem just appeared and happens regardless of light conditions. The screen adjusts brightness, but the keyboard will not illuminate now.

[analogika]

keyboard backlight switched on in Keyboard preferences in system prefs?

[GSixZero]

Seriously go into the bathroom where it's really dark, and I'm sure it'll work.

It actually has to be pretty dim for the keyboard to come on. Sometimes in a dim room the brightness of the screen can be enough to make it go off.

[xMetal]

well I did some more testing and Apple obviously changed the behavior of the backlight in 10.4. Previously, you could force on the keyboard at any time by using the buttons. I've done that in full sun, middle of the day. Now, it does need to be seriously dark. That sucks, because when it's just dim, and you'd like the backlight on full, you can't do it.

Stupid decision. I should be able to turn it on whenever I want, not when the computer thinks it's dark enough.

[mhuie]

I've *never* been able to force the backlight to come on during the daytime. Tiger did nothing to change this functionality.

http://docs.info.apple.com/article.html?artnum=86270

"These keys only respond in this way when the ALS is turned on. If you press the keyboard illumination control keys (F8, F9 and F10) and you see a dimmed graphic with the prohibitory sign (see below), the sensed ambient light is not low enough for the keyboard illumination to work."

[analogika]

Originally Posted by xMetal

well I did some more testing and Apple obviously changed the behavior of the backlight in 10.4. Previously, you could force on the keyboard at any time by using the buttons. I've done that in full sun, middle of the day. Now, it does need to be seriously dark. That sucks, because when it's just dim, and you'd like the backlight on full, you can't do it.

there was something wrong with your machine, then.

Because that has never worked on my Powerbook, nor on *any* of the machines we've had in the store since last fall, when I started working there.

[gwschreyer]

my keyboard backlight works, but it often turns itself off, even in the dark it is a zero intensity and Ih have to use F10 to bring it up again. It'll work for awhile then go to zero again.

I've just figured out how to reproduce the issue. Get into a dark room and turn off the lights and set the intensity to max. The backlight is on. Turn on the lights and press F10 just once, you'll get the prohibited signal. Then turn the lights off again. The backlight intensity will be zero again.

Happens every time

- gws