Incidentally, I do have a fine hard drive that I errantly replaced from my iMac G5 17". If it comes to that, maybe your friend would be interested in it.
The reason I replaced it was because I thought it was the source of my trouble, which turned out to be caused by my AirPort card. By the way, the hardware test did not show anything wrong with my airport card, either. As soon as I took it out, though, the problem disappeared.
First, here's the error Disk Utility spit out:
Mount of [drive name] succeeded
Verify and Repair disk [drive name]
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid node structure
Rebuilding Catalog B-tree.
The volume [drive name] could not be repaired.
Error: The underlying task reported failure on exit
Disk Utility stopped repairing [drive name] because the following error was encountered:
The underlying task reported failure on exit
1 HFS volume checked
1 volume could not be repaired because of an error
Repair attempted on 1 volume
1 volume could not be repaired
It says the mount succeeded, but it never shows up on the desktop? What could have caused this? Simple corruption or something else? I'm oblivious to the situation before it came here. For all I know, it could have been dropped or something...
Second, is the Airport card user-serviceable? Is it just behind the back shell? Also, thanks for the offer on the drive. I'm not sure what they're wanting to do yet, so we'll have to see. Thanks for your help.