Good evening everyone, i would like to share this based in my experience with iphones/ipad errors while restoring.
But before you come up sa HARDWARE REPAIR. It is much better to start with the basic method, like;
Update the ITUNES to latest version
Use another CABLE o tested CABLES
Restart your PC
Check your internet connections
Try restore to another PC
If you already did the basic remedy for Apple errors, maybe it's a HARDWARE PROBLEM.
These are the error code which corresponds to the possible defective component of your apple iphones/ipads.
Error 9, 14, 40 4009 - Memory/NAND Problem
Error 4013, 4014 - CPU Problem
Error 1, -1, 2, 3, 50 - Baseband Problem
Error -1, 3, 6, 16, 47, 48, 1669 - IMEI/Baseband Storage IC Problem
Blue Screen Error
Error 9, 14, 21, 40, 4013, 4014 - NAND Problem
Most Accurate & Most Common Error
Error 1 - Baseband CPU, Baseband PMU, 19.2Mhz crystal oscillator
Error -1 - Eeprom
Error 56 - NFC Circuit, Rear Camera Circuit
Error 4013, 4014 - CPU
Error 2005 - Battery, Voltage Supply
Error 9, 14, 40, 2009, 4005 - NAND
Error 3194 - Network, USB Cable, Charging Port Connector
Hope it can help !