IBook Rises From Dead After 3 Months! Baffled Family Member Needs Answers

Question

Hi
This is a rather long-winded post, so apologies/thanks to those of you patient enough to read to the end and to anyone who can shed some light on something that is baffling me regarding my iBook G3 700MHz (mid-2002 - I think).
This iBook has been an absolute trojan, working virtually 24/7 since I got it.
Anyway, one day about 3 months ago it just wouldn't power up. Nothing. No sound, no movement or any other sign of life.
I called my local Apple dealer and they told me about the PMU reset (mentioned elsewhere in these posts), which I did, and lo and behold the old beast fired up again. There was much rejoicing. All I had to do was reset the date and everything was sweet.
A day or so later I turned it off to take it to work with me, as usual. When I got to work and tried to start up nothing happened. Dead.
I tried the PMU reset again, to no avail. Nothing would get it going again.
I took it in to the dealer for them to have a look at. When I phoned back in the evening they said the logic board was dead and would need to be replaced at a cost of AU$1,000 (about US$800)! When I asked whether there wasn't an internal battery that could be replaced, I was told the iBooks don't have them - a fact which seems to have been confirmed in other posts in this forum.
I decided to buy a new iBook.
I've been waiting now for over 2 months for my new BTO iBook, but the dealer has lent me another iBook to tide me over until it arrives. The ridiculous wait for my new iBook is something I can cover in another rant, so I'll cut to the chase now...
Today, I was tidying up and decided that i should put my dead iBook away in its box and maybe one day I'd buy a second-hand logic board on eBay or something, fix it up and use it as an iTunes player or something...
Anyway, just before I put the dead iBook into its coffin, I thought I'd just give the power button one last push, for old times' sake.
The beast started up!
Again, there was much rejoicing. Again, all I had to do was reset the date/time.
So, as I type this on my loan iBook, I'm listening to iTunes via my SoundSticks on the old machine.
My question is this...
What has really happened to my iBook?
If the logic board is dead, why did the machine start up again after 3 months lying dormant?
If there is no internal battery, why have I had to reset the date/time both times it restarted? Wouldn't it be logical to think that some kind of battery was storing these settings?
Doesn't it seem reasonable to think that there is some sort of battery inside the machine which has slowly built up enough charge over the last 90 days to allow the computer to boot again?
Is it that there is in fact an internal battery built in to the logic board, and when the dealer told me it was "fried", all they really meant was that the battery was dead, but because it was on the logic board that the whole thing had to be replaced?
Obviously, I'm not going to turn the old iBook off again. I'll just put it to sleep when I'm not listening to music through it, but I'm just wondering whether any of you really smart people can tell me what's going on.
I really feel that this is miraculous and need some kind of clear answers to these questions.
Thanks for any help you can give me.
Matt
iBook G3 dual USB 700MHz   Mac OS X (10.4.4)  

Answer 1

Hi, Matthew. Welcome to Apple Discussions.
It is not uncommon for an iBook with a bad logic board to work intermittently.
There is no internal battery in an iBook. A capacitor holds the date/time information long enough for you to switch batteries, or for a short time without battery or AC power. The only battery is the main battery. If it has been left without use for some months, the capacitor has simply lost the date and time due to disuse and lack of power during that time.
When you do a PMU reset, this makes the time and date default, also.
Your iBook has been acting as one would expect, given the circumstances.
Mystery solved.