Monday, 22 October 2012

What to do when an external hard drive is not detected by Mac?

External hard drives are now household storage devices which offers huge amount of data to be stored on it providing fast and simple accessibility to files any-time, anywhere. Today, a computer user has so many varieties of external drive to choose from which perfectly meets his/her working needs. Among the most popular producers of external hard drives are Seagate, Toshiba, Western Digital, Kingston and others. Hard drives, also, are the most preferred devices that are used to take temporary back up of system data through transfer of files & folders (Copy & Paste). With a Mac machine at home, the external drive can be used as time capsules that will take incremental back ups of the data stored on the machine. In case of any unfortunate event, the Mac user can easily restore the files and folders from a time capsule.

Despite of its usefulness, there are several events that can harm the consistent performance of an external-drive and make it go undetected. One of the most unpopular event is when the OS X could not detect a connected hard drive and the data inside the drive is far away from user's reach. Undetected hard drive on a Mac could be a result of following reasons:


  1. Blame it on the hardware of the drive: No logical error found on Mac, but some hardware issues like loose or faulty wires, damaged surface, bad header and over heating could be few examples of hardware malfunction.


  2. Logical failures: Coming to the logical errors like file system corruption, unmountable drive due to file system failures, improper ejection of the drive corrupting the media. Here, we should remember that the drive in case of rude ejection can develop both logical as well as hardware errors.
Safe hard drive ejection tips for Mac OS X: Drag the external hard drive icon and drop it on the trash folder. Alternatively, use the key CTRL+Left Mouse Click, a pop-up appears, select the 'Eject' option to safely remove the attached hardware.

What to do when drive goes undetected:

Let's assume, a hard drive is abruptly detached from the system and now it fails to get detected by Mac on reconnecting.

  1. Make sure to check if the light on the hard drive is still active. This will ensure the drive is facing an error and is not entirely dead. A faulty cable of the drive could be one of the possible reasons for not getting it detected by OS.

  2. Connect the same drive on another system to check if that system detects it correctly. It happens many a times when a drive not detected on the system from which it was abruptly ejected and works fine when connected to other computer.

  3. Open disk utility and locate your hard drive. If corruption is serious, then disk utility will not show the drive. Here, users can also try safe mode to see if the drive is detected by the OS. If so, run verification from disk utility.

  4. Under Apple logo (on the top of desktop), click 'About This Mac'. Further, running the system report will confirm if its connected through the h/w.

  5. Run a hardware test for undetectable devices.
What if none of the measures works? If you are tired of trying all the tricks without any positive result then it is recommended to contact a professional. Hard drive components are sensitive and one never ever should try to experiment without proper knowledge. If your priority is to extract data which is still intact on the drive then try out a recovery application best suited for such drive corruption.