iPhone Duo — what to keep in mind with a foldable iPhone

Inside, the iPhone Duo has a foldable OLED measuring 7.6 inches diagonally. On the outside there is a second OLED of 5.4 inches, which you see when the phone is closed.

This is an important distinction for you. The outer screen is a normal display behind glass and therefore the cheaper repair. The foldable inner screen is the most expensive part in the whole device.

So when you send a request, tell us which of the two is affected. A drop on the closed phone almost always hits only the outside, which sounds like bigger damage than it is.

Apple has given the inner screen a nano-texture coating. That is the matte surface that breaks up reflections. It is part of the screen, not a stuck-on screen protector.

This leads to a clear rule: don't peel anything off. If something seems to be lifting at a corner, please don't pull at it, but bring the phone in. Once it is off, it won't come back.

For cleaning, a dry or slightly damp microfibre cloth is enough. Harsh cleaners, alcohol and abrasives have no place on this surface.

On every foldable, the hinge is where dust gets inside. Sand in the fold acts like sandpaper when you close the phone, on a surface that is softer than normal phone glass.

So watch out for two things: whether the phone still closes flush, and whether anything grinds when you open and close it. Both are early warning signs and good reasons to come by before the screen takes damage.

With every repair on a foldable, we also clean the hinge. That is the step that often prevents the next problem.

The typical first fault on a foldable screen is not a crack, but a bright line or flickering right in the crease. That is the spot that works mechanically every time you open the phone.

This kind of thing doesn't get better. It spreads, usually slowly over weeks. The sooner we take a look, the more likely it stays a manageable repair.

What you can do day to day: don't put the phone in the same pocket as a bunch of keys, and don't run your fingernail across the inner screen. The foldable layer picks up pressure marks.

The housing is made of titanium, with Ceramic Shield 2 on the front and Ceramic Shield on the back. Apple rates the Duo IP68, for up to six metres for half an hour.

Water resistance on a foldable is technically demanding, because the hinge is a moving opening. The rating applies to an unopened, undamaged device. After a drop or a repair, you shouldn't rely on it.

The Duo supports the Apple Pencil via USB-C. That is handy on the large inner screen and at the same time a good diagnostic tool.

If the pencil no longer responds cleanly in a certain area, the cause is the touch layer of the inner screen and not the pencil. Feel free to test this at several spots beforehand and tell us where it doesn't work.

Samsung has made foldable phones for several generations, and we have been repairing them from the start. The fault patterns are similar across manufacturers: fold, hinge, dust, seal.

That is why, with a foldable, we never look only at the one thing you report. The inner screen, hinge and seal are connected, and a fault in one place often has its cause in another.