Apple has announced that it will be replacing the 3TB hard drives of a small number of 27-inch iMac systems that were sold between the period of December 2012 and September 2013.

Apple has determined that the hard drives may fail under specific conditions, and so will be replacing the hard drives for free. The company did not specify the exact model numbers that are affected by the issue in its support page.

During the time period, Apple also sold other iMac configurations with different screen sizes and different hard drive capacities. All other iMac systems that do not have the 27-inch display and 3TB hard drive configuration will not be exposed to the potential failure of hardware.

The owners of the affected iMacs will be receiving an email from Apple to inform them that their systems have the issue and that their hard drives will be replaced. However, the owners should have registered their devices with Apple for them to receive the e-mail.

Users that were not able to register or were not able to receive the email for whatever reason, and unsure whether their iMac is affected by the problem can also go to the support page for this specific issue and enter the serial number of their iMac. Apple will then inform the user if their iMac is indeed affected by the problem and will need to have their 3TB hard drive replaced.

Replacements of the hard drives can be carried out by making an appointment with a local Apple Store, through an authorized service provider of Apple or via the Apple Technical Support hotline. For users who already experienced a failed hard drive for their affected iMac systems, they can reach out to Apple and have repair costs refunded to them if they have already had the problem fixed previously. However, the refunds will most likely be on a case-to-case basis, depending if the repairs were made by an official Apple channel.

Apple has recommended that users check if their iMac systems are affected by the problem. If their iMac is affected, users should immediately have their hard drives replaced, with Apple imposing a deadline of Dec. 19 or three years from the original purchase of the affected computer, whichever is the later date.

Apple also advised that users should make a backup of their hard drive first before having them replaced to keep all the data stored within.

Apple, however, did not clarify the conditions that could make the hard drives of the affected computers fail.