My wife's Time Machine drive, 6-month old external hard drive, suddenly developed problems preventing Time Machine from functioning. Disk Utility is unable to verify or repair the disk. What other tools are good for investigating disk repair issues? I'm not sure how severe the problem is yet. Some options are: * Call AppleCare. It might be a Time Machine or OS X induced problem. * Call Seagate. It might be the drive is failing. * Run fsck. Not sure if this is appropriate for a non-boot, external disk. * Buy a disk repair program. Seems silly to spend $100 on a utility to repair a $100 disk. Are there other tools, command line or otherwise, I should try? My fear is that 10.5.3 introduced drive-corrupting bugs into Time Machine. I've seen similar problems and I had to run DU's disk verify & repair on my own TM disk last night too.