Hello everyone. Im electronis engineer. I do these repairs everyday. The process is U send the motherboard only. After i received it. I remove the nand chip memory. I reprogram the nand ic. Which will erase all data. Refit the chip back on the motherboard. Full restore. I will test full function to the motherboard only if it comes complete. With the housing battery and screen. If i receive the board i will test only software. If board cannot be repaired 20 pounds will be retain as service CHARGE !! it takes up to 2 3 hours every time when this error comes on the phone. Just to try to fix it. Success rate about 70%. Depending on the state of the motherboard. Such as bent, corrosion liquid damage. Or other faulty components. Please fell free to ask me any question. Warranty for repair 30 days. Thank u. If u decide to send the phone. Address is 22B soho Hill. B191AA. BIRMINGHAM. WEST MIDLANDS. UK. any returns will be supported by buyer. The service takes only 3 days maximum after receiving the board.