iPhone Air User Complains of C1X Modem Failure, Claims Mobile Diagnostics Suggests Hardware Issue

iPhone Air was launched by the Cupertino-based tech giant last year, along with the iPhone 17 series. Apple markets the smartphone as the thinnest iPhone ever. The handset is powered by Apple's flagship A19 Pro chipset, similar to the iPhone 17 Pro and iPhone 17 Pro Max. The iPhone Air was also the first phone from the tech giant to feature its proprietary C1X modem. The company claims that this particular network chip is more efficient, while also being faster than the C1 modem found on last year's iPhone 16e. Now, a user has pointed out that the modem abruptly stopped working for their device.

iPhone Air Mobile Diagnostics Suggest Hardware Issue

In a post on the r/iPhone subreddit (via Wccftech), Reddit user u/itstheskylion claims that their iPhone Air had “no cellular network” on Thursday morning. The user claims that the C1X modem on their smartphone “died suddenly”. Upon failure, the user ran mobile diagnostics on his iPhone Air, which detected an issue with the phone's hardware.

The user was advised to check the condition of their iPhone Air's components. The smartphone was running the latest iOS 26.3 version, which Apple recently started rolling out. The user claims that his iPhone Air has been in a phone case since the day they bought the handset, and it has no physical damage.

In their responses to the post, the user also revealed that they have two eSIMs on their phone from different telecom service providers, but neither of them were working. The person even tried soft resetting and restarting the iPhone Air. While the user did not reveal whether the user's iPhone Air is covered under the Apple Care+ programme, and it is unclear whether the hardware issue will be covered under Apple's regular one-year warranty.

Apple launched the iPhone Air in India in September 2025 at a starting price of Rs. 1,19,900 for the base variant, featuring 256GB of storage. It was the first phone to feature Apple's new C1X modem. The tech giant claims that the C1X modem is capable of delivering twice as fast networking speeds and more efficiency than the C1 modem found on the iPhone 16e. The iPhone Air is powered by Apple's A19 Pro chipset, featuring a six-core CPU, five-core GPU, and a 16-core Neural Engine.

It's worth noting that this the first reported case of a modem related issue on the iPhone Air, and there is no indication that the issue is widespread. Recently, a report highlighted that Apple is also planning to equip the rumoured iPhone 17e with its C1X modem. The company is expected to unveil the low-cost iPhone model early next month, on March 4.