Old iBook reset PMU problem

have you tried resetting the nvram? I forget the key combination for an iBook but if you google you'll find the apple support document.

Also possible your PRAM battery may need replacing but I don't know how to check for certain.

Also worth trying booting off Apple Hardware test CD (which depending on your model may be the first os x install disk. Again I forget exactly how but see manual and/or google. That would enable you to test for certain hardware faults. If your PRAM battery has died you nay find you need to do nvram and Pmu resets in order to get booting from cd by holdin down c on startup to actually work.

I'm sure others will know more that you can try but that's about all I personally can think of. Good luck

 

You may not be able to, but you may. Basically you hold down C immediately after pressing the power button, and keep it held down until it appears to be booting off the CD. Sometimes this doesn't work if your NVRAM is corrupted, in which case an NVRAM reset may fix it (this happened recently on my PowerBook). On the Powerbook this is hold down Command, Alt (option), P and R on boot, but I don't know if the iBook is the same. For some reason, although the Apple support documents didn't say this, for me it only works with right command key. Then after I'd powered off and back on holding down C worked.

There's also safe mode, and single user mode (see google) that might let you do some things, but I don't know much about these.