Error 21, what's the first thing I should try?
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.
Is this a good question?
2 Comments
Yea I have a 5c that shows error 40 and my 6s went to restore when I tried to update
by Austin hanson
@austinh2017 try what @refectio said below.
by Gigabit87898