For the last three weeks, CNET has been stress testing the iPhone Duo's hinge on a livestream. After over 451,000 folds, the hinge is showing signs of wear.
CNET says the hinge started feeling looser at the 390,000-fold point, and by 440,300 folds, there was enough of a shift in the mechanism that the screen didn't open in full before the machine closed it again, and there was no distinctive snap. It is 5 to 10 degrees from the fully open state and can be opened fully by hand.
The wire we use to open the phone screen would withdraw before the screen was in the fully open position, but it would then sort of "coast" the rest of the way down. But between 12:30 and 1 a.m. this morning, around 440,300 folds, the screen would no longer have time to open all the way before the Fold-a-Phone caused it to close again.
The iPhone Duo hasn't been removed from the folding machine, and the test is continuing. CNET says the device is still operational and maintaining other screen positions, with no signs of cracking or other failure.
The site plans to continue folding the iPhone Duo until it hits predetermined failure conditions that include loss of power, sensors failing to detect the screen properly, and screen blackout.
Apple hasn't shared the results of iPhone Duo hinge testing it likely did internally, or given an estimated fold lifespan.
The iPhone Duo is equipped with OLED panels sourced from Samsung Display, and Samsung's screens have undergone certified third-party fold testing. The display used for the Galaxy Z Fold7 passed a 500,000-fold durability test. Apple probably isn't using an off-the-shelf Samsung display, but CNET's testing already suggests the iPhone Duo's OLED panel is on track to match.
The combination of the display and the strength of Apple's hinge design will determine lifespan. At around 450,000 folds, the iPhone Duo would last over a decade at 100 folds per day.
CNET's livestream will continue until the iPhone Duo fails. The livestream runs on weekdays from 10 a.m. Pacific until 2 p.m. Pacific.
