I recently got my hands on an iPhone 4 running iOS 4, and I attempted to update it to iOS 7 this past weekend. However, I ran into a problem during the process via iTunes, which prompted me with a message stating there's an issue with the phone that needs it to be updated or restored. I've tried multiple methods, including updating, recovery mode, and DFU mode. I even switched out the charging cable and tried different USB ports on my laptop, but it keeps reverting to that recovery screen. Is there anything related to iTunes that I haven't attempted yet?
2 Answers
It sounds like there might be an issue with the cellular baseband. If it was working fine before you attempted the update, that might indicate a deeper problem, but it's worth checking out.
When you try to update, does it say it was successful or does it fail with an error? If it seems to pass but still reverts to recovery mode, it could be an issue with the home button being stuck or recognized as pressed. I've had luck using 3uTools to exit recovery mode, and sometimes just disconnecting the USB cable helps if it thinks the home button is constantly pressed.

Really? Even if the phone was used regularly? That’s concerning!