Had another request yesterday to have a look at another USB drive that failing to connect to the computer.
Assumed worst case that the brains of the drive were cactus and that a memory transplant would need to take place.
Opened it up tonight to discover that two of the pads holding the data lines down on the usb connector were cold joints and had broken free, simple fix and working straight away.
So just a heads up for people to please be nice to their usb drives when transporting, inserting and removing them.