[操作疑難] How to recover bad HFS partitions?

Helping a buddy ask...
Was copying files from one HDD to another HDD when suddenly the HDD crashed and becomes inaccessible...
Dude used Disk Utilities to fix the HDD, but HDD becomes unmountable and thus cannot access any files inside.
HDD is apparently in HFS Journaled format

What should he do?  The application prompts that dude to copy out all the files into another HDD, but he cannot even access the botched HDD in question.

Any help?