Hinge Damage Suspected Behind iPhone Duo Screen Cracks as iFixit Teardown Points to Stress Hotspot in Foldable

A small number of Apple's new iPhone Duo foldable phones have developed cracked inner screens within days of launch. Independent teardowns now point to the device's hinge as a likely cause.

The $1,999 iPhone Duo, Apple's first foldable smartphone, went on sale Oct. 23 and quickly sold through its initial supply. Within hours, users began posting photos and videos online showing damaged displays. Many of the failures followed a similar pattern: a crack or line of damaged pixels starting at the fold and spreading horizontally toward the edge of the screen.

Apple has not publicly commented on the reports.

A sheared hinge part

One possible explanation came from YouTuber CuriousHagi, who subjected an iPhone Duo to a punishing test that included exposing it to dirt and bending the hinge backward, according to AppleInsider.

When he tried to close the phone, it would not shut fully. When he reopened it from a partly closed position, he heard a loud snap, and the inner screen showed a large white area of damage running from the crease to one side.

He then took the phone apart. After removing the display, he found that a hinge element connected to an upper support plate had sheared off at the same spot where the screen crack began.

The broken part was slightly thinner than neighboring hinge elements, which could make it more prone to breaking. He also found heavy crush marks on a nearby part of the mechanism and what appeared to be an impact mark on the underside of the display.

AppleInsider said the most likely sequence was that the hinge failed to mesh properly, a section sheared off, and the broken piece struck the screen and cracked it.

The test involved deliberately abusing the phone, which owners are not expected to do in normal use.

iFixit's findings

Repair specialist iFixit reached a related conclusion in its own teardown of the device.

The company combined CT scans, teardown footage and Apple patent filings to build a 3D model of the hinge. It then compared the model against photos of damaged screens posted by owners. iFixit found that the breaks tend to cluster where a flexible cable connecting the phone's two halves crosses the central hinge support.

That cable has accordion-style pleats that let it move as the phone folds, and it runs through a gap in the middle of the hinge. Several structural edges meet and move in that area, which could concentrate stress.

In one simulation, iFixit found that the hinge's center support bar did not drop far enough when the phone closed. As a result, the folding screen pressed down onto it, creating a stress hotspot.

iFixit also raised a second possibility: curved guide rails that rise during folding could interfere with the screen if they don't move as designed.

The company said it had not definitively identified the cause and that more investigation was needed.

Dust gets into the hinge

Dust may also play a role.

The iPhone Duo carries an IP68 rating, meaning it is designed to be dust-tight and to survive submersion. In iFixit's dust test, however, fine particles reached the hinge, which then began making crunching sounds. Owners have described hearing a similar crunch before bright or green lines appeared across their screens.

iFixit noted that less dust entered the iPhone Duo's hinge than in rival foldables it has tested, including Samsung's Galaxy Z Fold 8 and Google's Pixel 11 Pro Fold.

Most repairable foldable yet

Despite the screen concerns, iFixit gave the iPhone Duo a provisional repairability score of 5 out of 10. It said that was the highest score it had ever given a foldable phone, though the rating depends on Apple making replacement parts available.

The outer screen and the phone's two battery cells were relatively easy to remove. The batteries use an adhesive that releases with an electric current, which iFixit praised.

"The easy battery removal alone is something we'd like to see on every foldable," iFixit said.

The inner display and hinge, however, are the hardest and most expensive parts to repair, which pulled the score down.

"For a first attempt, Apple has done well," iFixit concluded. "But you'd better baby that screen, Duo owners."

Hiding the crease

The teardowns also revealed how Apple minimizes the visible crease that has long been a complaint about foldable phones. The inner display uses a matte nano-texture finish with tiny rounded bumps that scatter reflected light. Some pixels near the fold are oval and arranged in different orientations, which an Apple patent suggests helps reduce visual distortion.

Still a small problem

So far the failures appear to affect only a small number of phones.

AppleInsider said it checked on Oct. 24 with sources at Apple Genius Bars in seven stores, including four flagship locations. None had received devices for service or returns because of broken screens. A follow-up check late Sunday found one case across all of those stores.

"So far it's not as widespread of a problem as the sensationalist videos propose," AppleInsider wrote. It noted that the number of cases will rise as more phones reach customers, but that it is not yet clear whether the failure rate will.

Early hardware failures are common with major new product launches, particularly in categories as mechanically complex as foldable phones. Samsung, Google and other manufacturers have dealt with hinge and screen problems in earlier generations of their own foldables.

Some owners have pointed out that Apple heavily promoted the durability of the iPhone Duo's hinge at its launch event, raising expectations.

What owners should do

Experts advise owners not to bend the hinge backward or deliberately stress the device. They also recommend keeping it away from sand and fine dust. Users who experience screen damage should report it directly to Apple rather than relying on social media.

Many buyers have opted for AppleCare+ coverage because inner-screen replacements on foldable phones can be expensive.

Demand remains strong

The reports have not dampened demand so far. The iPhone Duo sold out shortly after its launch, and some delivery estimates stretch into January. According to supply-chain reports, Apple has asked suppliers to increase production orders by about 30%. Apple has not confirmed those figures.

Apple shares were trading slightly lower on Monday. The company reports fiscal fourth-quarter results on Nov. 2, and it has said it has more product announcements planned this week after launching a redesigned iPad mini on Monday.