The chip-off data recovery method is an advanced data extraction technique used when all other methods (including JTAG) are not possible.
This involves physically removing flash memory chips from your device and acquiring the raw data with specialized equipment.
iPhone data recovery with chip-off or JTAG is not possible. An iPhone/iPad’s memory is encrypted with AES-256, an open and very strong form of encryption with no known weaknesses. The only option is to restore function to the original components, enter the passcode and make an iTunes backup.
JTAG data recovery is used when a device can’t be read normally, usually when a device is logically damaged (bricked), or secured with a passcode.
This involves connecting to the device’s test access points (TAPs) and instructing the device’s processor to transfer the raw data from the memory.