If this technique did not work, you can use Data Recovery software. The principle is simple: if a partition is damaged, but its files are intact, the software accesses it. He cannot in any way “repair” the partition. He can simply Data Recovery from the broken hard drive, and copy them to another medium.
So be sure to bring another disk or a USB key to save your precious files. Free or paid, these software will generally do the same job. Paid tools simply offer more Data Recovery advanced features, which sometimes help to locate files not found for free software.
Start with a free solution instead. Almost all of this free software runs on a PC. On Mac, the effective solutions are mostly paid. First check whether your external hard drive is recognized or not by your operating system. In the first case, it means that the system is accessing the partition, but not the data.
You can then use one of the many free file recovery software on damaged partition or files deleted by mistake. These include the excellent Recuva , but PC Inspector File Recovery or PhotoRec also do a great job. On the other hand, if the disk is not recognized by the Twitter system, it means that the partition is inaccessible.
In this case, it will be necessary to use partition recovery software. We recommend the excellent (and free) Test disk– which also has a Mac version! With a tutorial on how it works: Test Disk step by step . But Ease US Partition Recovery and MiniTool Partition Recovery (on Windows) are also very effective.