Apple's first foldable phone, the iPhone Duo, is facing fresh durability questions after owners reported that its hinge jammed following a drop, then returned to normal on its own. The reports add to the scrutiny of a device that went on sale on 23 October priced from $2,000.

One owner felt unusual resistance in the hinge after dropping the phone on a hard floor, according to phone news outlet PhoneArena. When the owner tried to unfold the handset about an hour later, the hinge made a loud noise, but the phone then unfolded normally. The owner checked the crease for a bulge, a possible warning sign of display damage, and found no visible problem.

Other owners have described the same sequence: resistance in the hinge, a loud pop or crack, and then normal operation. PhoneArena suggested that a hinge component may have moved out of position and later shifted back into place, but stressed that the exact cause has not been confirmed.

The outlet warned that forcing the phone open can make things worse. Some users who ignored the resistance and kept unfolding the device experienced the internal screen cracking loudly. Its advice to owners is to close the phone and visit an Apple Store if the hinge does not move normally.

Apple has said only a small number of devices have experienced the problem, and it is offering replacements to customers with inner-display faults. Even so, reports of damaged devices have continued to appear online, and PhoneArena said one customer could not get a repair because requests for repairs and replacements were apparently too high for Apple to keep up with.

A possible explanation for the failures emerged on 7 November, when PhoneArena reported a claim from Weibo leaker Kang that the problem comes from defective material used by one of Apple's hinge suppliers, rather than a flaw in the hinge design itself. According to that report, Apple can trace the affected batch using serial numbers. The claim remains unverified, and Apple has not publicly identified the cause.

Repair specialists at iFixit, whose findings were cited in the same report, concluded that internal hinge components were pressing into the electronics beneath the screen. Other reports have suggested slight hinge misalignment on some units pushed internal parts upwards into the display, breaking it from behind. Fine M-Tec, a South Korean company linked to foldable display and hinge component production, has rejected late-October allegations that its materials were behind the reported quality problems.

For owners, the practical message is clear: if the Duo resists opening, do not force it. The hinge may settle back into place, but pushing through the resistance risks a cracked inner display and a costly repair.