Chosen Solution
So this phone shows error 21 during iTunes restore and says invalid serial number during 3utools restore. What should I try first? EEPROM reflow? Baseband Reball? EDIT: After reflowing the EEPROM, it shows 40 now.
This might help… https://www.theiphonewiki.com/wiki/ITune… From 3uTools Error 20, 21, 23, 26, 28, 29, 34, 37 These errors typically occur when security software interferes with the restore and update process. Follow Troubleshooting security software issues to resolve this issue. ‘‘In rare cases, these errors may be a hardware issue’’. If the errors persist on another computer, the device may need service. I wouldn’t get into reflowing IC’s, I’ve suggested that to you before. Especially the Baseband…no good can come from that. I believe it’s a software issue. Dig into the 3uTools documentation to find some options before playing with the hardware.
