Apple has confirmed that a small number of iPhone 8 devices sold between September 2017 and March 2018 contain logic boards with a manufacturing defect.

iPhones that are affected with the problem may experience unexpected restarts, a frozen screen, or won’t turn on. Units affected were sold in Australia, China, Hong Kong, India, Japan, Macau, New Zealand, and the United States. The issue doesn’t affect the iPhone 8 Plus or other iPhone models.

To resolve this issue, the company has implemented a logic board replacement program, which is free of charge.

To determine whether your phone is eligible for a replacement, you’re encouraged to use the serial number checker on the replacement program website.

If your handset qualifies for a free replacement, you can receive maintenance at an Apple Authorized Service Provider or Apple Retail Store. You can also contact Apple Support to use the company’s mail-in repair service.