External Hard Drive is a storage device that provide simplest way to store and transfer the data from one device to another. Sometimes, you receive an error message "external hard drive not recognized/detected" when you connect and try to access the data. The issue you can check and resolve by yourself, follow the steps given in this infographic.
Data is recoverable from all kinds of external hard drive when it is not recognized. Before data recovery, you should always remember not to do any operation on the external hard drive, which may prone to data loss and decrease the chances of data recovery.