Apple's first foldable phone, the iPhone Duo, did not pass a well-known durability test just one day after its market debut, according to the JerryRigEverything channel.

The YouTube channel, which has been stress-testing foldables since the first generation, said, "Most do survive," and added, "The iPhone Duo did not."

Dust Jams the Hinge

Even with an IP68 dust and water resistance rating, the Duo struggled when presenter Nelson covered it in sand and dirt.

Granules entered the hinge, preventing the magnets from pulling the device fully shut, leaving it slightly ajar.

The bend test proved harsher; bending the opened phone backward left a permanent green line on the inner display. A second bend produced additional lines, after which the inner screen stopped responding to touch, MacRumors reported.

Inner Screen Scratches Easily

The outer display, protected by Ceramic Shield 2, endured only faint marks at level 7 on the Mohs scale.

By contrast, the flexible 7.6-inch inner screen scratched at level 2. Its matte nano-texture coating masks most marks while the screen is on.

Nelson also warned that repairing the inner screen could cost around $1,000.

Software Complaints Too

Early owners have posted clips showing apps struggling with the new form factor. One widely shared video shows a video app shrinking into a small window instead of expanding to fill the larger screen when the phone is unfolded.

The iPhone Duo is Apple's most expensive iPhone to date, priced higher than many used cars in Pakistan. Veteran iPhone users have noted that it does not address the primary issues of foldable devices.