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

A user of the recently launched iPhone Air has reported a sudden failure of the device's C1X modem, which has led to a loss of cellular connectivity. The complaint surfaced on Reddit, where the user detailed that upon waking up on Thursday, their phone was unable to receive any signal. After running a mobile diagnostics test, the user was informed that a hardware issue was detected, despite the absence of any visible physical damage to the device. Launched in September 2025, the iPhone Air boasts of being the thinnest model in Apple's lineup, featuring the advanced C1X modem that is marketed as being faster and more efficient compared to the C1 modem used in the iPhone 16e. This incident raises concerns about the reliability of the modem in this new model, as users expect high performance from Apple's flagship devices. The company has not yet responded to this specific complaint, leaving many potential buyers apprehensive about the durability of the iPhone Air's hardware.