As the new foldable smartphones from Samsung Electronics, "Galaxy Z Fold 8, Fold 8 Ultra, Flip 8" (hereafter Galaxy Z8), set a record for the biggest hit ever with 1.44 million domestic preorders, they were caught up in an unexpected controversy over "corner depression." The issue surfaced in some units of the passport-style Z Fold 8 with a 4:3 ratio, which gained popularity despite a price approaching 2.3 million won, as well as in some Z Fold 8 Ultra models. Samsung Electronics said this was "a normal design characteristic for durability and protection," but users' doubts have not easily subsided.
The controversial "corner depression" is a phenomenon in which pressing a specific area among the four corners of the screen by hand makes it sink inward as if there is some play. The problem is that even within the same model, the location and degree of depression vary. Some products depress at the top right, while others show depression at the top left, and some users say all four corners feel solid. Among users, accounts say the depression is most pronounced at the top right corner, followed by the bottom right. By contrast, some say the left corners are relatively less depressed or barely noticeable. This did not occur in the previous Galaxy Z Fold 7.
Samsung Electronics clarified its official position by leaving a reply under the name of a "Samsung Electronics mobile phone manager" to a user inquiry posted on the Samsung Members community regarding the corner depression. Samsung Electronics explained that a "buffer (cushion) structure" for durability and protection was applied to the outer corners of the main display on the Galaxy Z Fold 8 and Z Fold 8 Ultra. The Samsung Electronics mobile phone manager said, "A design was applied to secure clearance in that area to reduce interference between internal display components or the impact of pressing," and added, "Because of this, when a specific spot is pressed lightly, it may feel like there is minute movement." The person also said, "This is a normal design characteristic applied to protect the display and improve durability," explaining that it does not affect product performance. However, if there are concerns about product defects, the company advised visiting a service center for an accurate diagnosis.
If Samsung Electronics' explanation is accurate, the corner depression is not a product defect but a kind of "cushion" intentionally created to enhance the durability of a foldable phone. But what users are curious about is not simply "it depresses or it doesn't." If this is a design Samsung Electronics intended, users say a specific explanation is needed as to how much depression is normal, whether all four corners have the same structure, and whether differences in depression by corner are also normal. In fact, some users are asking, "If the corners don't depress, is that actually a defect?"
As a result, users have gone so far as to disassemble the product themselves to check the structure and submerge it in water to verify whether there are any durability issues. IT YouTubers are independently conducting durability tests related to the corner depression. They ran experiments submerging Z Flip 8 devices in water. The Galaxy Z Fold 8 and Fold 8 Ultra have IP48-rated water and dust resistance.
IT YouTuber "UNDERkg" confirmed that the top right corner of their own Z Fold 8 also depresses and then pressed the corner while the device was fully submerged in a water tank. In the test, even after pressing the device multiple times underwater, no bubbles appeared and the screen did not turn off. UNDERkg then removed the device after soaking it in water for 30 minutes, and the smartphone worked fine. However, after wiping off the exterior moisture and inserting a thin tissue into the gap at the depressed corner, water did seep out from inside the device.
There is also a YouTuber who disassembled the device. The YouTuber "CuriousHagi" found after disassembling the Z Fold 8 that there is a seat at the device's corners that can secure it when folded, and that in the Galaxy Z8 series, the magnet portion creates an empty space that sinks slightly inward. Because the magnets at the top and bottom are different sizes, the degree of depression appears to vary, which seems consistent with a buffer-type structure. In the previous Galaxy Z7 series, the magnets and frame were the same height in a flat structure, so there was no corner depression.
They also assessed that, unlike the right, the left side of the screen has only a slight step at the edge, making the degree of depression different in all areas. CuriousHagi said, "Some argue that if durability is the reason, all four corners should be the same, but the areas with magnets are prone to attracting magnetic debris, and if the device is accidentally closed while debris is stuck to the magnet, the display can be damaged. So it appears they maximized the empty space on the right magnet area, which is relatively freer than the left side where the display circuitry needs to go," adding, "When pressing slightly on the area where the waterproof tape is attached to the bottom of the display, you can feel a very slight curve; because it has some thickness and is a foam-type, stretchable material, it may adhere more over time and create variation in depression depending on individual usage environments."
CuriousHagi also added, "Even if water gets inside, it appears to enter outside the waterproof tape, so the waterproof function should not be affected," and "When water enters through the hinge area, the waterproof structure continues to prevent water from getting into the internal circuitry."
Shin Min-su, a professor in the business administration department at Hanyang University, said, "Consumers are satisfied not only by the convenience of use that a product provides but also by receiving convincing explanations when there are functional controversies," adding, "To quell consumers' questions, it is necessary to go beyond simply saying 'normal design' and explain more specifically why the degree of depression differs by corner, whether variance can occur by unit, and what range is considered normal."