Early adopters of the iPhone Duo, Apple's debut venture into the foldable market, are sounding the alarm over a recurring hardware failure. A growing number of users are reporting a distinct visual defect on the inner foldable panel—specifically, a vertical and horizontal line—which appears to be linked to a mechanical failure within the hinge system.

Image source: scary_duck23 (Reddit) Image source: scary_duck23 (Reddit)

The failure follows a consistent narrative: users describe the hinge becoming unexpectedly rigid, requiring forced effort to fully unfold the device. This resistance often culminates in an audible "pop" or "crack," immediately followed by the appearance of permanent lines on the inner screen. According to various testimonials, particularly on the iPhone Duo subreddit, the damage manifests as a central vertical line with a horizontal branch extending toward the right side of the display.

Image source: Vishnu_RK (Reddit) Image source: Vishnu_RK (Reddit)

The timeline for these failures varies wildly. While some owners experienced the malfunction within a few hours of unboxing, others managed several days of use before the screen failed. Many of the affected users emphasize that they have not mishandled the hardware and, in several cases, are seasoned foldable device users who are familiar with the nuances of these screens.

Seeking resolution, impacted customers have contacted their mobile carriers and Apple support. While Apple has reportedly agreed to replace the defective units, the process has been hampered by severe stock shortages. At the time of writing, replacements are particularly difficult to secure for the high-capacity 1TB and 2TB configurations.

Image source: Bitter_Offer7123 Image source: Bitter_Offer7123

While a definitive cause has not been officially confirmed, the evidence strongly points toward a hinge malfunction. The fact that the display damage is preceded by physical resistance and a popping sound suggests a mechanical failure that puts undue stress on the OLED panel. It is possible that this is a localized issue affecting a specific production batch, as the majority of users and long-term reviewers have not encountered this specific defect.

Apple iPhone Duo

If your device is exhibiting these symptoms, it is highly recommended that you contact Apple support immediately to register your claim and secure a replacement unit as soon as inventory allows.

Via: iPhone Duo subreddit