Target Disk mode makes the target (victim?) drive into an insensate appendage of the host computer, just as if it were physically installed as an internal drive of the host.
If your 'Book's drive then responds to Apple's disk utilities from the G3, mirabile visu. If not, resist the urge towards hara kiri while you get hold of some more powerful disk utilities: LaCie's Silverlining, FWB's Hard Disk ToolKit, Intech's Hard Disk SpeedTools or ATTO's utility. Silverlining and HDST certainly use Apple's partition scheme for HDDs, and almost certainly so do the other two.
If your dud drive mounts on the desktop of the G3, you are already a long way forward. (It is not impossible that the 'Book's HD data cable became loose, or failed.) Indeed, use of DiskWarrior 2.1.1 (or 3.0.x under OS X) to straighten out a corrupted file directory may be all that you then need to see your files again. DW will do nothing, however, to replace a dud HD driver, for which you will need one of the foregoing. Silverlining has a good GUI, which is both intuitive and revelatory of the drive's condition. Just do not invoke any option to repartition the drive, recreate the file system or erase the drive. All of these preceding utilities (except DW 3.0.x) need that you work in OS 8.6 or 9.1+.
If, after all this, it comes down to a mucked-up partition scheme, you are in professional recovery territory. This is rare, and most often the result of mechanical rather than software failure.
Best of luck, and success, to you.
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