There are both bad and good news for iMac users.

Last week, Apple acknowledged that a number of the 3 TB hard drives used in their 27-inch iMac devices, particularly those sold between December 2012 and September 2013, may fail under certain conditions. Users who could be affected are those who purchased iMacs with the Apple Fusion Drive, which pairs the 3 TB HDD with a smaller-capacity, faster flash drive. The configuration is mostly available for higher-spec iMacs and are used by professionals who need large-capacity storage for their media content.

The good news is that the Cupertino-based company has set up a replacement program for the said devices. 

According to the post on the Apple support page, the company is already contacting affected iMac users via the email addresses they provided during registration. Those who didn't register when they bought the products but suspect their iMacs need replacement can check if their units are covered in the replacement program by using the iMac's serial numbers. Owners can also go to an Apple Store or an Apple Authorized Service Provider for the replacement. In addition, those who think that their devices are already failing can contact Apple Technical Support immediately for replacement. 

For those who will go directly to service providers, Apple recommends that they back up their data first before getting the replacement done. Replacing the 3 TB hard drive on the iMac will set the device back to its factory settings and aside from rolling back the data, users will also have to re-install the operating system and other applications. 

Apple has not provided any details on how the 3 TB hard drives on iMacs could fail, but most tech observers say that the 27-inch models' hard drives might have been part of a faulty batch of hard drives that manufacturer Seagate released some time ago.