You really have to be able to better identify the iBook model,
for a more exacting reply to happen. It's a matter of specs.
If the model is a white G3 iBook, it would look like a G4 iBook; and the RAM
amount in question would be more in line with a G3 than a G4. Or the RAM
spec is incorrect for the iBook; if not a hardware issue at fault.
•Apple iBook Specs (ALL iBook Technical specs: G3 to last G4)
http://www.everymac.com/systems/apple/ibook/index-ibook.html
•Lookup Mac Spec by Serial No, Order, Model & EMC number, Model ID:
http://www.everymac.com/ultimate-mac-lookup/
These use (P)ATA/IDE hard disk drives, so a Serial ATA will not work.
Depending on the specs of the computer, a drive could be matched up.
http://www.ifixit.com/Device/iBook
The correct RAM chip for the model, is important, and a limited amount of
RAM is on the logic board; so the upgrade slot has to be of correct spec.
For an example, the first G4 iBook (800MHz) had 128MB RAM onboard.
It could also use up to 1024MB upgrade in the empty RAM slot, for a total
1.12GB PC-2100 DDR266 200-pin SO-DIMM. Model identifier PowerBook6,3.
So if you can better identify the iBook in question more exact info may be
forthcoming, or at least additional resource links for researching parts.
Good luck & happy computing! 🙂