Apple has determined that a small percentage of iPhone 7 devices may show "No Service" in the status bar (even if cellular coverage is available), due to a component that has failed on the main logic board. These affected units were manufactured between September 2016 and February 2018 and sold in China, Hong Kong, Japan, Macao, and the U.S. See below for iPhone 7 model numbers that are covered in this program.
If your device exhibits the symptom described above, Apple will repair your device, free of charge. If you've already paid for a repair, Apple will contact you by email to arrange for reimbursement. If you believe you paid for a repair related to this issue, and have not received an email from Apple by the end of March 2018, please contact Apple.
Below are the three model numbers that are eligible for this program. You can find the model number on the back of your iPhone 7.
A1660, A1780 - China
A1660 - Hong Kong, Macao, U.S. (includes Puerto Rico and U.S. Virgin Islands)
A1779 - Japan
Choose one of the service options below to have your iPhone 7 repaired. In all cases, your iPhone will be sent to an Apple Repair Center for service.
● Apple Authorized Service Provider
● Apple Retail Store
● Apple Technical Support
More details at the link below!