Some iPhone Duo foldable phones have broken screens in the same location, raising suspicions of "a systematic error".

On October 23, Jesse Dalton in Dallas (USA) bought an iPhone Duo for $2,000 and returned home to show it to his wife. But the excitement soon turned into a nightmare. Even though he had only opened and closed the machine about 4-5 times and hadn't even installed it yet, he felt like the hinge was stuck. Trying to fold it, he heard a loud "pop" sound, then bright lines appeared on the screen, including a line along the fold and a strip running across the screen on the right side.

"I felt absolutely panicked," Dalton told WSJ.

Meanwhile, Shane Basinski's iPhone Duo in Melbourne (Australia) also broke in the same way after about 6 hours of use. "I treated it as carefully as porcelain, even equipped it with a case right after opening the box," Basinski said.

Both Dalton and Basinski will likely be replaced by the Apple Store. But they are not an isolated case. Many information about similar incidents have been reported by anonymous users on online forums such as Reddit and X.

Responding to CNBC on October 26, an Apple representative said "we are aware of the issue affecting the internal screen of a small number of iPhone Duo". However, the company did not specify how many devices were affected, the cause, and whether a recall policy would be applied.

The fact that Apple did not mention the cause makes many people wonder whether this is a bug phenomenon on some products, or a systemic problem.

"The problem may be due to 'sensitivity' in the hinge tolerance, or in the way the screen is supported during the folding process," commented Francisco Jeronimo, Vice President of global devices at market research firm IDC.

After studying the internal structure, technician Shahram Mokhtari of iFixit, a reputable device repair unit in the technology world, hypothesized the reason why the Duo screen failed: the weakness in the hinge impacted the microscopic electronic components below the screen.

"Some people described how they were opening and closing the phone when they heard a cracking sound, but still tried to continue operating," Mokhtari said in the video disassembling the device. "Right at the location where the damage occurred, the hinge structure was a little different."

Also according to Mokhtari, stuck debris or manufacturing errors in the hinge can damage the folding screen - a component that is already "very vulnerable". In fact, Samsung's first folding phone in 2019 also encountered many problems, such as OLED stripes running across the screen, causing the Korean company to delay the launch of the phone.

Similarly, Jiemian News (China) also "dissected" the iPhone Duo and found that the problem may be due to the central support bar not retracting into the correct position when the device is folded, thereby creating great pressure on the screen. In addition, the arc-shaped guide rail that supports the hinge's movement also protrudes higher than surrounding components during the folding process. If it doesn't move as designed, the rail has the potential to "cause discomfort and negatively impact the screen."

Suspicious of Apple lowering the quality of the chain

Quoting a Foxconn employee, JW Insights, the financial and economic news channel under Xinhua News Agency, said that in the context of intense production pressure, Apple had previously decided to "lower some quality inspection standards to ensure supply", thereby increasing the probability of defective products being distributed to the market.

Also according to the source, the iPhone Duo line has urgently replaced another batch of materials to fix the problem. Currently, production activities are not affected, while the goods reserve plan remains the same.

"Apple may not tighten the iPhone Duo quality testing process because it wants to take advantage of the opportunity to dominate the folding screen phone market before its competitors," JW Insights commented.

Li Nan, founder of technology company Angry Miao Technology and former vice president of Meizu, assessed that the incident may be related to the way Apple coordinates with the supply chain in China. Sharing on 36kr (Korea), he said that in the past, Apple engineers had to "work hard" at the factory and work with their partners to immediately solve chain problems.

According to Nan, inside folding smartphone hinges there is generally a structure called "keel" that helps the screen bend many times. If the support frame is misaligned by even 0.1 mm, the edge of the frame will press on a single point on the screen during the process of opening and closing the phone. This point is under a lot of pressure, which may not cause problems in the short term, but after many times of opening and closing, this pressure point will damage the screen.

He said the error may be related to tolerance issues, not design. There are two pieces of evidence: the defect location is extremely uniform, all in the same place on the hinge, and durability testing shows no cracks after 11,000 folds, meaning the design is durable enough, or the problem arises from improper assembly during mass production.

Typically, final inspection of the hinge is at the run-in stage of the supply chain. However, Nan said that compared to previous years, the number of engineers in charge of this stage has decreased by "about half". Besides, they are not given as many rights as before.

"This is not necessarily something that the Chinese supply chain cannot handle," Li Nan said. "The problem is that Apple has become increasingly disconnected from the Chinese supply chain over the years, and process and quality engineers are said to no longer have many opportunities to fully communicate with Apple. The risk was predicted long ago, but ignored by senior management."

In fact, the close relationship between Apple and Chinese supply chain engineers has been documented before. According to New York Times, a few weeks before the first generation iPhone launched in 2007, Apple co-founder Steve Jobs suddenly wanted to change the screen design. For other companies, this decision could delay progress by at least several months. However, the factory in China mobilized 8,000 workers in the middle of the night, giving each person a cookie and a cup of tea. Only 30 minutes later, the newly designed production line began operating.

In 2018, Isabel Ge Mahe, in charge of Apple's operations in China at that time, visited the iPhone 8 line at the Pegatron factory in Shanghai. According to Chinese media, when a new product enters the production phase, the company sends more than 100 engineers to be on duty at the factory, coordinating with the Pegatron team to detect and handle problems that arise during the production process.

With the iPhone Duo, the complexity of the hinge was once described by Apple Chief Operating Officer Sabih Khan as "one of their most challenging products". However, according to Nan, Apple only sent about 30 engineers to work on the production line in charge of the hinge at the Foxconn factory. For comparison, in the period 2012-2017, the number of engineers Apple sent to Foxconn was nearly 2,000 people for the entire material supply chain, production line and quality control.

According to 36kr's speculation, the decrease in the number of Apple engineers working at Foxconn may be related to the company's transfer of personnel to India, where there is a shortage of engineers. Previously, the company had set a goal of increasing the proportion of production in India to 50% of total global output within two years.

Apple does not comment on the information.

iPhone Duo is Apple's first folding screen phone, officially on sale from October 23 with a starting price of 1,999 USD. The device comes in two colors: white and blue, uses the A20 Pro chip and iOS 27.1 operating system. Apple equips the product with a custom-designed hinge system, a titanium body and a 48-megapixel main camera system. When folded, the device uses a 5.4-inch external screen, while when opened, the 7.6-inch screen is aimed at entertainment and multitasking needs.

Bao Lam summary

• Apple speaks out about the iPhone Duo screen crack phenomenon
• iPhone Duo is disassembled, revealing the reason why the screen cracks easily
• Some iPhone Duo have cracked and streaked screens