Chosen Solution
Good day, A customer of mine had his phone updating however he unplugged the phone accidentally while it was being updated. Now, when i put the phone in dfu mode and restore. Its giving me an error 51. I am aware that this is a board related issue. However, can anyone advise if they experienced this issue so that I can know weather it is the NAND or BBCPU or whichever may be the issue.
Try restoring the phone using 3Utools. Hopefully that works. If not then I’m sorry to say it’s probably the NAND needing to be reprogrammed. Try getting it restored at an apple store as it could be your computer having issues communicating with the phone properly with iTunes etc.
it sounds like the IPSW file format is corrupted. the customer might have run a beta or jailbroken version of iOS which can usually be 1 of many reason for error 51 delete the existing saved IPSW in the iTunes directory for Mac Launch FinderClick Go from the menu barScroll down and click ‘Go to Folder’Type in “~/Library” and click GoClick and open the iTunes folderOpen the iPhone Software updateDelete the.IPSW files for Windows Go to C:\Users\Your Computer Name\AppData\Roaming\iTunes\iPhone Software UpdateFind the.IPSW file and delete or you can press CTRL +A (control all) and hit the delete on your keyboard.Update the iPhone again.trying an update after this procedure should force iTunes to download a new file format
try downloading a fresh IPSW image currently Apple only sign 11.4.1 and Proceed to update the iPhone hope this works if that doesn’t work. you might wanna give FoneDog toolkit IOS system recovery a try cheers
