After 3 weeks and over 451,000 bends, the iPhone Duo hinge finally starts to fail

Three weeks ago, we put Apple’s new iPhone Duo on our custom foldable phone test bench, the Fold-a-Phone, to find out how many times it could bend until it broke. It’s not completely broken yet, but the hinge has started to break.

I initially detected some looseness in the hinge movement yesterday during our afternoon live stream. It became apparent that the iPhone Duo wasn’t opening with the same firm sound I was used to hearing. When I left the office last night at 6 p.m. it still opened completely flat.

But now the screen no longer opens completely flat. Instead, it unfolds almost all the way but leaves a few degrees of angle in the hinge. Watch the video below to see for yourself.

After reviewing the sensor data we collected and the photos and videos we constantly take during the testing process, we determined that the changes in opening force and movement began to occur around the 390,000 point Tuesday afternoon and gradually developed through last night.

The wire we use to open the phone screen would pull out before the screen is in the fully open position, but then it would sort of “roll” all the way out. But between 12:30 a.m. and 1 a.m. this morning, or around 440,300 folds, the screen would no longer have time to open completely before the Fold-a-Phone caused it to close again.

How serious is this problem? In the grand scheme of things, not much. The phone still works and maintains other screen positions without issue. There are no cracks, signs of a more visible crease or other failures.

This issue is not sufficient to meet our established failure conditions in the Duo, which include loss of power, sensors failing to detect the screen where it should be within the time limit, and screen failure. The phone is only about 5 to 10 degrees from the fully open state, and it can still be moved all the way by hand (but without the distinctive sound and feel it had before).

Join CNET’s iPhone Duo live stream on YouTube weekdays from 1-5 p.m. ET, where you can follow along live and watch the Fold-a-Phone do its thing with a Duo.

https://youtube.com/live/V5CYMpUAzl0?feature=share

Chances are, if you had purchased the phone and experienced this behavior, you might not even notice it at first. And remember, by the time this started, we’d subjected the iPhone Duo to the equivalent of nearly 12 and a half years of bending (assuming 100 bends per day) – well beyond the number of bends we’d expect from even an avid user.

Apple hasn’t publicly stated the expected number of bends the iPhone Duo will experience, so we’ve had to speculate. Estimates within CNET range from 500,000 (matching Samsung’s rating for the Galaxy Z Fold 8) to 1.5 million. But while we don’t yet know for sure how bad the hinge action will get, and therefore what the final figure will be, what we saw today represents the first significant step toward failure.

We will continue. And we hope you’ll stick with us, here and on our daily live streams, to see what else happens.

Matthew Murray

Laboratory Director

As CNET Group Lab Director, Matthew leads the Labs team, which helps coordinate and conduct product testing for CNET and other Ziff Davis editorial brands, including PCMag and ZDNET. He previously spent eight years as head of testing at Future plc, and before that eight years as an analyst and editor at PCMag. His technology writing has also appeared in publications such as Computer Shopper, ExtremeTech, Tom’s Guide, Laptop, and Backstage.

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