Hi Mike,
There are two functions for checking the HDD in the JB7. If you go to 'Main' --> 'Settings' --> Maintenance' --> 'Disk Test', this function runs a full check on the HDD.
If this shows problems, then you can use 'Main' --> 'Settings' --> Maintenance' --> 'Map Disk', this function will attempt to fix those problems on the HDD.
If this is successful, then the 'Restore music' function should work.
Regards,
Peter.