Hi Iain,
I have gone through the process of copying my music from a B2 to a couple of JB7s, about 130GB/ 1500 albums and did find out one very important fact when using a USB or HDD to restore to a JB7.
That is when you format the USB or HDD to FAT32, the JB7 will see the USB/HDD, but due to a quirk in the JB7's workings, the JB7 cannot read the files off the USB/HDD.
I found that the way around this was to:
1. Format the USB drive in the normal way (this isn't necessary if the devoice is already FAT32 formatted)
2. Then plug the USB into the JB7 and wait for 'USB OK' message'.
3. Select 'USB Functions' --> ''Backup music'
4. Let the JB7 backup about 10 music files to the USB/HDD device.
5. Stop the backup and unplug the USB/HDD device.
6. Plug the USB/HDD into a PC.
7. Using Windows Explorer select the USB/HDD device and go into 'hardfi' folder, then into the 'music' folder.
8. In the 'music' folder, select and delete all of the contents (so you now have an empty clean ''hardfi/music' folder set).
9. Plug the USB/HDD device into your B2's USB C port.
10. Run 'USB Functions' --> 'JB7 Functions' --> 'Backup to C' and let that run to completion.
11. Plug the USB/HDD device into the JB7.
12 On the JB7 run 'USB Functions' --> 'Restore music'.
13. Let the restore run to completion.
The reason for doing the above is that the JB7 was designed in the Windows 95 era. Whilst the FAT32 format then and now are the same, there was a feature change inside the format (known as long file names) which causes the JB7 to not recognise the 'hardfi' and 'music' folders. By running through this process, because the JB7 has created the folders, then it will recognise those folders when the B2 backup is done into them.
Regards,
Peter.