new iBook problem...

[Fran Dollinger]

Ok, so, I wrote in last month about my new iBook doing alot of freezing 
up and was told basically to send it in and have Apple take a look at 
it. So, I can follow directions and I did send it in. I got it back 
Wednesday and the note said they replaced the processor. Ok, good. Now 
it doesn't freeze any more. I did install an additional 128MB chip from 
another iBook (a 800MHz one, mine is a 600MHz). Yesterday I put the 
'book to sleep for a few hours while I ran into town and when I came 
home and lifted the lid she started right up . THEN after about 30 
seconds I get this loud whirring sound. What's that? I don't know. I 
did a hard shut down (nothing else worked), waited a few minutes and 
started it up again. Everything was fine. Today the same thing happened 
after it being asleep again, another hard shutdown....now (just now) it 
started the loud whirring noise and is still doing it as I type 
this.... What is this....anyone?

Thanks,
Fran