iFixit tears down the iPhone Duo: best foldable repair score, but a screen problem

iFixit gave the iPhone Duo a provisional 5 out of 10 for repairability, the highest it has ever given a foldable phone. 9to5Mac and TechRadar both report the score. It is provisional because replacement parts are not on sale yet.

iFixit is careful to say this is not an endorsement of repairing the Duo. Fixing the inner screen is still, in its words, going to be a bear.

The score comes from a mix of good and bad news:

• Good: both batteries come out easily, and the outer screen is simple to remove.
• Good: the trim around the inner screen came off in one piece.
• Not so good: the inner screen and the hinge take a lot of work to reach and replace.
• Not so good: dust still finds its way into the hinge.

Apple used the same battery trick it uses in ordinary iPhones: electrically releasable adhesive. Adhesive is just glue. This kind lets go when you send a small electric current through it.

iFixit used its own tools or a 9V battery on the release tabs, waited, and the glue let go. No alarming bending or prying. 9to5Mac says iFixit called it the best battery removal it has seen in a foldable.

The Duo has two battery cells, and 9to5Mac lists their capacity:

• Larger cell: 11.567 Wh
• Smaller cell: 7.506 Wh
• Combined: 19.073 Wh

A Wh, or watt-hour, is a way to measure how much energy a battery holds. Bigger is more.

In real life If your Duo battery ever fades, a repair shop could swap it without wrestling the whole phone apart. That is rare for a foldable.

Every foldable has a crease where it bends. iFixit says no foldable has fully solved that, "not even the Duo, no matter how many Apple fans call it creaseless." But the inner screen looks remarkably smooth, and iFixit found out why.

The screen has a matte finish called nano-texture. Under a microscope it looks like tiny rounded bumps packed together, a little like bubble wrap. The bumps scatter light, so reflections get fuzzy instead of bending sharply across the fold.

When iFixit took the nano-texture layer off, the crease was arguably even more visible than the one on the Galaxy Z Fold8. So the finish is doing real work.

There is a second clue. Some of the screen's red, green and blue dots, called subpixels, are oval and point in different directions. iFixit points to an Apple patent about reducing diffraction artifacts, which describes varying subpixel shapes so reflected light makes less noticeable patterns. That could be another way the crease hides.

A hinge is the joint that lets the phone fold. The Duo's is a small machine. iFixit describes gears, springs and a chain of metal joints that share the work of bending, a bit like a metal watchband.

Curved guides let those joints move as though their pivot points were inside the screen above them. The goal is to bend the display without stretching or squeezing it too much. Springs take some of the force, so the phone stays where you leave it.

Why it matters: the screen is made of more than ten ultrathin layers and adhesives that glide past each other as it folds. Think of bending a stack of paper: the outer pages travel farther than the inner ones. The hinge has to let every layer slide just enough.

This is the part owners care about. iFixit says some people hear a noise while opening or closing the phone, then see a small line down the fold and a bright line across the display. One owner reported it within six hours of buying the phone, and another before finishing setup.

iFixit says Apple is offering replacement units for now. Out of warranty, inner display damage costs $999.

To look for a cause, iFixit built a 3D model of the hinge from teardown footage, patents and CT scans. A CT scan uses X-rays to see inside a device without opening it. It compared that model with the places where screens broke.

The breaks cluster near the spot where the gap for the display cable meets the center hinge support. That is not exactly where the cable passes, but slightly lower, where several edges meet and change how the thin display is supported.

One possibility iFixit simulated: the center support bar fails to drop far enough as the phone closes. The curved fold then presses down onto the bar and creates a small stress hotspot close to the reported damage.

The catch: this is a theory. iFixit stops short of saying what is causing the damage, and TechRadar notes further investigation is needed to know for sure. Apple has not confirmed a cause, and iFixit itself raises other candidates, such as the center pivot getting stuck.

Some owners say they cannot see any damage to the screen or hinge other than the lines. That fits, iFixit says: a small fault in the tiny electrical connections can knock out an entire row or column of pixels.

iFixit has run a glowing-dust test on foldables for years. It puts the phone in a bag of fluorescent powder, works it open and closed, then takes it apart and follows the glow under ultraviolet light.

The powder is finer than typical beach sand. The results for the Duo:

• Most of the powder stopped at the adhesive barriers around the electronics.
• Some of it reached the moving parts of the hinge, and the hinge started crunching.
• Compared with rivals: the Duo collected less visible powder than the Galaxy Z Fold8 and the Pixel 11 Pro Fold in earlier tests.

The Duo has an IP68 rating. That means dust-tight, and water-resistant to 6 meters for 30 minutes. But iFixit says the test is not an IP test, because IP ratings measure what gets into the enclosure, which does not seem to include a foldable's hinge. Cleaning those moving parts means removing the flexible display and its supports.

iFixit wrote that it hoped Apple would solve this problem, but the Duo seems to share the sand-phobia of its folding cousins.

Apple's service prices, as listed by iFixit:

iFixit says the $999 inner screen repair costs about half as much as a whole new device. It will sell replacement screens as soon and as affordably as it can, but warns this is a complicated part that will not be cheap.

The cover layer is the nano-texture surface on top of the OLED. OLED is the screen type where each dot makes its own light.

iFixit likes that Apple provides a way to replace the cover without sacrificing the OLED. That is an improvement over the early Galaxy Fold, where reviewers famously killed displays by peeling off what looked like a screen protector. Apple's procedure still calls for specialized fixtures and precise alignment, so it is not a simple DIY swap.

Time is a factor too. iFixit estimates a similar repair on the Pixel 10 Pro Fold takes a typical do-it-yourselfer 3 to 5 hours. The Duo should be faster, since you do not have to go into the other side of the device to disconnect the display. But replacing all that adhesive is delicate, finicky work.

Apple borrowed familiar tricks from its regular iPhones. There are pentalobe screws, the five-sided type iFixit says it is not a fan of, and iFixit notes the Duo has four of them at the entrance instead of two.

The outer display came off intact, including the plastic frame that gave the site grief in its iPhone 18 Pro teardown. That matters because several internal repairs go through it, and nobody wants a battery repair to turn into a screen repair.

Clips and screws hold the outer display and back cover alongside their adhesive seals. In a pinch, those fasteners let you put the phone back together while you wait for fresh adhesive, though without water resistance.

The cable between the two halves is folded into accordion-like pleats so it can move with the phone. It has a lot of responsibility: one battery charges through it, and it carries video and audio data across the gap. iFixit says the symptoms of the broken screens point in another direction than this cable.

• Owners: keep the phone clean. Sand and dust are the Duo's main enemy, and iFixit's closing advice is to baby the screen and skip the pocket sand.
• Buyers: the batteries are easy to replace, but budget for a $999 inner screen repair if you do not have coverage.
• Waiting for answers: the crack theory is unconfirmed. If you see lines on the fold, Apple is offering replacements for now, according to iFixit.
• Repair fans: this is a step forward for foldables, even at 5 out of 10.