Supplier-material flaw, not hinge, may explain iPhone Duo

A new report says the display failures affecting the iPhone Duo are likely down to defective materials supplied to Apple, not a flaw in the phone's hinge design. The claim comes from a Chinese source familiar with the matter and shifts attention from engineering to the supply chain.

According to that source, Apple’s hinge design is sound. The origin of the problem is said to be faulty raw materials used by one supplier in component manufacture. Apple can apparently identify problematic shipments by device serial numbers, which would let the company spot potentially affected phones before a failure and offer replacements to buyers.

Reports from users and teardown findings

Shortly after the iPhone Duo launched on 23 October (1 Aban), some users reported hearing a cracking or popping sound when opening or closing the device. Cracks subsequently appeared along the fold line and, in some phones, a horizontal band of white, inactive pixels developed across part of the screen.

Several users also reported feeling a small bump under the display at the start of the crack. iFixit experts previously concluded that internal hinge components were pressing on electronic parts beneath the display and damaging them.

The iPhone Duo uses a complex hinge made up of gears, springs and metal linkages. Apple designed curved guides to reduce pressure when the phone folds, but some analysts had suggested the folding mechanism might not operate exactly as intended and that internal parts could press up against the display.

Other reports described a minor hinge misalignment in some units, a condition that could allow internal components to exert upward pressure on the display and cause breakage.

Apple reportedly spent about a decade developing its foldable iPhone and entered the market later than other major manufacturers. As a result, a hardware defect in the first generation could carry higher costs for the company.

If the new claim about defective supplier materials is correct, the root cause would lie in the supply chain rather than an engineering error in the hinge. Apple has not published official details about the cause of the display failures.