no backlight on powerbook when waking from sleep


I hook my powerbook up to a monitor at work, and before OS X final, I could not switch back to the built-in display without shutting down.

Yesterday I was excited to find the ability there to switch back and forth, so at the end of the day I put the 'book to sleep to take home. However, when I got home and woke it up, all was fine but no backlight!!!

Fortunately with an LCD you can still just barely make out the screen, so I logged in and switched resolutions to 800x600 and back which fixed it. But it was not permanent - next sleep session produced the same problem. After restarting, it was cleared up.

hopefully this little bug will be cleared up with 10.0.1...


When your notebook is asleep, is the video card actively drawing lines on the screen with no backlight? I've noticed a decent amount of wierdness about sleep in this OS, and I even got it to crash completely by putting it to sleep in the middle of network traffic from 9 and X and waking it back up.

Anyway, If I put my notebook to sleep and the battery comes out for even a moment it's all over. Anyone else seen this? If you haven't I wouldn't recommend you try to recreate it. There's a nasty bug in the sleep code somewhere.


I've never been able to get the backlight to work after sleeping, either with the Public Beta or with the final. I also have a Wall Street PowerBook.

I've tried different combinations of things to test this out. I've tried installing with or without OS 9.1. I've tried HFS+ vs. UFS. I've tried mixing and matching my RAM modules. I've tried reverting back to the stock HD. I've tried all sorts of other software configuration on the OS X end. Either way, I've never got it to work.

Sleep for the most part works in OS 9.1, although there are some combinations of software that can produce the same effects.

My theory is that there are all sorts of ways to control the power management hardware in a Wall Street powerbook; all sorts of different commands. I'm theorizing that I have a hadware problem that causes the ways that OS X talks to the power hardware to not fully work completely. This hardware problem would also manifest itself under certain conditions in OS 9. But the problem is usually manifest in OS X because it addresses the hardware differently than OS 9.

I have a three year extended warranty on my machine, so to test this theory, I took it back to the retailer and said "Sleep, a function which is supposed to work on this machine and this OS, doesn't". The "technician" ran some "diagnostic software" which found some "problems", so right now the machine is on its way to Apple for logic board and PMU replacement.

If sleep works when the machine comes back, I will have to conclude that either my particular board was bad, or that there was a run of Wall Street boards that had some flaw in them.

If my Power Book comes back working, then I would assume that you, hotani, suffer from the same affliction according to your description of your symptoms.

As far as your battery thing, Theed, there's a TIL article on this at



my problem is annoying, but not permanent. If I am hooked up to an external monitor, then change the display back to the wallstreet, then sleep, it will not come on. However, if I restart the machine it is fine (until I hook up another monitor)...

I don't think mine is worth fixing if it is a hardware problem - this machine is on its way out to be replaced by Ti :).