Apple's iPhone Duo went on sale last Friday, and within hours, users began reporting cracks and lines appearing at the center of the inner display. The Verge reports that the damage follows a similar pattern across social media images, usually a black spot or crease above the hinge, with lines spreading on the right side of the screen.
On Monday, Apple acknowledged the issue and said it is replacing damaged units, but did not say how many phones are affected. According to GSMArena, Apple's response came via a statement to 9to5Mac, where the company called it a "small number" of Duo units and advised owners to contact AppleCare as soon as possible to secure a replacement.
The debate now centers on what is actually failing. According to The Verge, iFixit's teardown suggests the hinge, not the screen itself, may be the root cause.
iPhone Duo hinge issue explained
Shahram Mokhtari, lead teardown technician at iFixit, told The Verge that the problem comes from the hinge assembly, where a series of gears, springs, and joints work together to let the device close flat. The design tries to avoid a deeper crease by giving the screen more space to bend gently when closed, but at one specific spot, the flexible inner screen appears to push up against part of the hinge.
Mokhtari describes the inner screen as "extremely sensitive" and says a pick or sharp tool near the edges can break it. In social media photos of damaged Duos, there is often a black spot where the damage is focused, which he says is where metal hits the display. iFixit's teardowns show where the hinge transitions, with the center support bar making space for a crossing flex cable and creating several edges that could be responsible.
A user with a broken Duo said they felt resistance around the internal hinge while showing the phone to a friend, kept opening it, and heard an audible crack before the screen broke. YouTuber CuriousHagi, who tested the Duo with dirt in a durability video, captured a similar break in the same spot and later found in a teardown that part of the hinge connected to the central bar had snapped, according to The Verge.
