Apple announced a free replacement of the faulty power button on a small percentage of eligible iPhone 5 smartphones and is offering  refund to those who have already paid to resolve the issue.

Apple Inc., the biggest smartphone and tablet manufacturer, is offering a free replacement of the faulty on/off buttons on its previous flagship iPhone 5 units. The Cupertino tech giant officially announced Friday, on its support site that the problem may be found on models manufactured through March 2013 and affects only a "small percentage" of iPhone 5 users. The tech company did not reveal the exact number but lets customers check for the eligibility of their iPhone 5 units with the device's serial number.

Apple said the on/off button- or the sleep-wake button as Apple calls it- caused the iPhone 5 to respond intermittently or cease to react to any action performed by the user. While a recall of this sort for its premium handsets is a rare scenario, Apple addresses any known problem by offering a free fix. In 2010, Apple encountered some issues with the iPhone 4 that affected the device's antennas, causing network blackouts. The problem was resolved by offering free cases, CNET reports.

The latest replacement program involving Apple's last year's flagship starts Friday, but in the U.S. and Canada. The program will extend to the other parts of the world starting May 2. Users can turn in their affected iPhone 5 units to Apple at a retail outlet and official dealerships, or even mail them.

"Apple has determined that the sleep/wake button mechanism on a small percentage of iPhone 5 models may stop working or work intermittently," the support page reads. "iPhone 5 models manufactured through March 2013 may be affected by this issue. Apple will replace the sleep/wake button mechanism, free of charge, on iPhone 5 models that exhibit this issue and have a qualifying serial number."

Before handing over the affected iPhone 5 to the repair center, Apple has a checklist for its customers.

Users must enter the device's serial number on Apple's support page to check for free repair eligibility. Go to Settings > General > About to get the serial number of the device. If the handset is eligible for a free replacement, users need to back up their data on iTunes or iCloud, turn off mobile tracking, erase all content and settings, including any phone passwords or security patterns and remove any phone covers.

The free replacement comes with certain restrictions even for a handset with serial number. For instance, if the phone is damaged in any way that affects the on/off button, the problem needs to be fixed before the button replacement.

However, if eligible iPhone 5 customers have already paid for a replacement due to the issue then Apple has you covered for a refund.