iBook G4 optical drive keeps rejecting disks - bad drive?

Today my iBook G4 has started rejecting CDs from the drive. It will insert fine, make its normal noises, then the point when it normally starts spinning there's a big "thump" sound, followed by no spinning. Then it ejects normally. I'm not a pro, but this seems to me like something is broken, causing it not to spin. The drive worked 3 weeks ago (fortunately) as I reformatted and reloaded a bunch of software. Any advice other than "take it to an Apple store" or "replace the drive"? I know I'll have to do one or the other, unless somebody else has any thoughts. Thanks!