Powerbook wakes and sleeps on its own

Question

Just the other day my Powerbook started acting really strange. It will goto sleep on it's own, just like that. Usually I wake it up, but it won't always wake up - I click, press keys, hit the power button and get nothing. And then it may eventually wake up.
But it will also get into this cycle, where it wakes up, then goes back to sleep all on its own without the screen coming on. I know this because I hear the DVD drive do it's little clicking thing everytime it wakes up.
The other really odd thing, is that it sometimes has dimmed the screen off, and I have to use the function keys to turn the screen back on. Other times I press the function keys to bring the screen back and I can see very faintly the screen contents, and that the screen should be at full brightness, but it's not. I feel like this thing is posessed.
Now the strange coincidence is that the latch for the screen stopped working the exact same day. Related? I'm not sure. I did have to take it with me, so I put it to sleep by closing the lid and putting it in a tight case, and it appeared to have stayed asleep. I thought maybe the latch controlled the sleep mechanism, but it appears to be the angle the screen is at.
I Thought this was maybe related to that overheating trackpad thing, but my console reads something different. Just "System Sleep" and "System Wake". There is nothing about overheating showing up.
Now the other strange thing, is that the light on the latch button has never really worked correctly as far as I Recall. Sometimes it's pulsing when I'm working, sometimes it's off when it's sleeping, I don't even know the correct behaviour anymore.
Now last thing is that my illuminated keyboard doesnt seem to work. It's as if the computer doesn't know it exists, I press the Funciton keys and nothing happens, and I can't find it anywhere in the sytem prefs.
So I've done the usual, reset the PMU, startup in open firmware and reset nvram etc, Reset the PRAM, system is upto date. I know this thing should go in for service, but it usually takes a bit of time the way things are set up in Canada. This is my only computer and I can't be without it at the moment. Any suggestions to make this machine more usuable for the time being would be greatly appreciated. It can go for hours with no problems, then BAM, it just wont stop sleeping.

Answer 1

I kind of stumbled upon the source of the problem. My Ambiant Light Sensor puts my computer to sleep. If I cover the left speaker grill near the top - where the sensor is I guess - then it puts the computer to sleep about 5-10 seconds later.
Odd.
And now I can wake my computer up by setting off the sensor again, or covering it - but it takes longer. I cover the grill, and then 5 or 10 seconds later the computer wakes up. But the screen wont be on. So I have to put the computer to sleep again with the ALS, and then wake it the normal way (usually the keyboard).
So I guess the solution here (temporary) would be to find a way to deactive the ALS. Is there some file somewhere in the library I could move around? Thanks.