回答“no entry sign on OS reinstall”everything indicates that the Hdd is dead, damaged, (go out and purchase a new drive). but wait you can see it in Disk Utilities run restore etc but it will not load the iOS 1. Unmount the Hdd then format the drive then remount the drive. re boot from disk util run restore install the latest iOs via your netwk. find a USB to access the system. as with last reply.