As you suggested, connected the external hard drive to my desktop, the drive was scanned and then i unplugged via the eject hardware icon, reconnected the drive to the rock, then went into storage and the drive was visible so connected to the folder. Still seems to work
Main Sonos speaker is connected to the router. I have just checked the cable was okay, it was so when i plugged in again it found the speaker. At the moment all seems fine.
Thanks