[Mallrat]

I've had a 15inch powerbook for a month now.

Lately it has been shutting off randomily. I'll be doing something, and it will work fine (like type this post).

Then I'll go grab a water and I come back and the computer's asleep.

When I try to wake it up, it shuts off the light like it woke up, but I can't see anything on the screen and I have to restart my computer.

It's so weird.

I guess if I shut off never go to sleep my computer might work fine, but I want it to go to sleep so it doesn't get overuse or over heat.

I was having some funking things happen for a few weeks that I think was due to bad memory.

I bought some new Edge ram and even moved the installed ram to the other slot to see if that helped.

So far none of the weird freezes and crashes that was occuring previously have come back.

I thought I was all set, but I guess not.

Does this have anything to do with memory?

Could this be a logic board problem?

I just noticed this problem yesterday and I think it might have been right after I installed Tiger. Could this be the cause of it that Tiger has some messed up sleep issue?

Thank you.

[nsbio]

Do you have any other weird symptoms such as keyboard backlighting or ambient light sensor suddently getting stuck in one setting? Or do you have the sleep light misbehaving, that is, not coming on when the PB is asleep and/or occasionally staying on when the computer is awake? I had exactly the symptoms you described, in addition to those I just mentioned. I brought my 15'' Rev D PB into the Apple store and they fixed it (very quickly, by the way). It turns out that it was a hardware problem, NOT memory-related. The repair slip said that the part to have been replaced was ALS ASSY, which presumably stands for Ambient Light Sensor Assembly.
So call up Apple/walk up to the Apple store - they should help you. It seems that RevD 15-inchers are rather finicky animals (or rather, fruits ). It is not that they are troublesome overall (my friends have five of those among them, and none of them has had any problems) but they appear to be less reliable than other Apple books. But even so, I would not trade mine for anything else, except maybe for the next revision Powerbook (duh!).
Good luck and do not forget to post when your problem is taken care of.