iPhone Duo hinge starts failing after 440,300 folds

The iPhone Duo’s hinge has started to degrade after 440,300 folds — the first measurable mechanical shift in CNET’s ongoing automated durability test. That number represents roughly 12.5 years of daily use at 100 folds per day, far exceeding what even a heavy user would realistically do. The Fold-a-Phone rig, CNET’s custom-built testing apparatus, has been cycling the device nonstop since early October.

At first, the iPhone Duo opened with a firm, consistent snap and settled fully flat every time. But around the 390,000-fold mark on Tuesday afternoon, sensor data began showing subtle changes: the opening force dropped, motion became less precise, and the hinge’s resistance softened. By last night, the behavior was unmistakable.

The screen now stops short of full extension, leaving a small but visible gap of about 5 to 10 degrees, and no longer clicks into place. It can still be nudged open the rest of the way by hand, but without the original tactile feedback or audible cue. CNET notes this is not yet a functional failure: the display remains intact, sensors correctly register screen position, and no software errors or blackouts have occurred.