updated 10:36 pm EDT, Thu June 19, 2014
UK repair company says unofficial USB-to-Lightning adapters may burn out crucial circuit
Reports of iPhone 5 units with charging issues has lead a UK repair shop to note that unauthorized third-party charging accessories used with the iPhone 5 (and possibly other Lightning-equipped iPhones) may be causing damage to the iPhone itself, specifically by burning out a specific power-management integrated circuit (IC) labelled "U2." The circuit helps flow power to the battery and charging circuitry and also controls some USB functions as well as sends power to the sleep/wake button.
The problem does not seem to be caused by certified "Made For i" (MFi) accessories, reports the firm called "mendmyi," but rather by "knock off" and counterfeit versions often produced in China and Taiwan, reports iMore. Illicit chargers in those countries have killed or electrocuted several iPhone users, which prompted Apple to offer free replacements to customers in the region who brought in a counterfeit charger. The iPhone maker has also recalled its own European five-watt chargers over safety defects.
A fake Lightning charge cable that burned out
Unofficial USB adapters and USB-to-Lightning cables appear to be the issue. They tend not to sufficiently regulate electrical current, causing the IC chip in the iPhone 5 to burn out. Some owners have reported similar problems with uncertified chargers and the iPhone 5c as well.
When this happens, it causes iPhones to be unable to charge the battery past one percent, and may also prompt failures to turn on even when connected to a power source, or unexpected shutdowns. Bloggers have documented that most of the cheaper chargers offered outside the "MFi" program bypass important safety components in order to keep the cost down.
"The cause of this component becoming faulty is really quite simple -- third party chargers and USB leads," Mendmyi said in a statement. "The original Apple chargers and USB leads regulate the voltage and current to a level that protects your valuable iPhone and prevents it from damage. Charging your iPhone using a third party charger or USB lead that does not regulate this as much allows for larger variables in voltage and current, this then damages the U2 IC and can leave you with a seemingly dead iPhone 5."
The company reporting the issue says it can fix the problem by replacing the IC, but it costs about $112 US (£66) to repair. The firm recommends people use the original charger and cables (or MFi alternatives) to avoid the issue.