Federico Cerva runs a iPhone and iPad repair business in London. Instead of replacing batteries and broken screens, he focuses on more complex fixes, often acting as a subcontractor for other mobile phone shops around Europe that mail him broken Apple products that he diagnoses and repairs with a microscope and soldering iron.

For the past six months, Cerva has been receiving large numbers of iPhone 7 and iPhone 7 Plus devices—often 10 to 15 per week—with a similar issue: one of the pads that connects the audio chip, which is located on the motherboard near the SIM card tray, has come loose.

The early symptoms are a grayed-out Voice Memos icon, a grayed-out “speaker” button during phone calls, or intermittent freezing. Eventually, the phone can get stuck on the Apple logo instead of powering on. Cerva calls the issue “loop disease,” in reference to “touch disease,” a similar issue that affected thousands of iPhone 6 and iPhone 6 Plus units starting around 2016.

“It’s worse,” Cerva said of loop disease. “It’s actually worse.”

Apple confirmed in an emailed statement that the company is researching the issue.

"We are looking into a very small number of reports affecting the microphone on iPhone 7, if a customer has a question about their device they can contact AppleCare,” an Apple spokesperson said.

But Jessa Jones, who started iPad Rehab, a company in New York state that repairs Apple products on behalf of other shops and trains technicians, says she has seen an “epidemic” of the issue over the past six months.

“It’s an old age disease, just like anything else,” she said. “It’s not going to happen very often in a young phone. So the 7s are just now getting to the age where they are off-warranty and they are still reasonably new enough to be worth fixing, that they’re really coming into this problem just now.”

Jones and Cerva disagree about what causes the loop disease. Cerva blames small drops that cause the pad to become disconnected, while Jones suspects that it’s due to the phone getting repeatedly bent during use.

But the fix, Jones and Cerva agreed, is straightforward: they remove the audio chip, then solder a small segment of wire underneath it to repair the connection. Cerva can complete the repair in just 15 minutes, he said; Jones said that a qualified shop should be able to carry out the repair for between $100 and $150.

Online, there have been other reports of audio and boot problems with the iPhone 7 and 7 Plus. A number of other technicians have documented similar issues on YouTube, and there are many forum posts by customers who have the issue and don't know how to fix it.

Last month, MacRumors reported that an internal document distributed to Apple Authorized Service Providers that affected audio during phone calls. It’s not clear whether that issue is related to the loop disease identified by Cerva, Jones and the other technicians.

In response to questions about this story, an Apple spokesperson asked when the deadline was, but didn’t reply further by the time of publication.

Jones also expressed concern for cell phone repair workers around the world. Since smartphone users can go weeks or months without turning their devices off and on again, she said, it’s possible that when a lesser issue like a cracked screen forces a user to bring a phone into a shop, the technician will power the device off and on, only to discover that the device won’t boot because of previously undiscovered loop disease.

“They’re going to be forced to accept responsibility for a problem they didn’t cause,” she said.

An example of the speaker grayed out. Image: iFixit

Jones also believes that the bending board can cause problems with a Qualcomm chip that lies on the same “fault line” on the circuit boards of some iPhone 7s, which can cause a “No Service” message. Earlier this year, Apple issued a recall for iPhone 7s with Qualcomm chips that were displaying the same error.

To Jones, that’s insufficient. She believes that Apple should offer free extended Apple Care Plus warranty.

“I think that Apple maybe could acknowledge that it’s unlikely, that a significant chunk of these phones aren’t going to make it to two years,” she said. “They could just elect to give everyone that coverage for free.”

Cerva, though, points out that Apple’s misfortune has allowed him to build a thriving business.