Error 9 and Error 14 both mean your iPhone lost USB connection during restore. Error 9 = mid-process disconnect. Error 14 = firmware file corrupted during transfer.

Error 9 — connection dropped

Cable disconnected, port lost contact, or security software interrupted the stream.

Fix:

Apple-certified cable → direct USB port (no hubs) → disable antivirus → DFU restore.

Error 14 — corrupted firmware

IPSW file damaged during download or altered by security software.

Fix:

Delete existing IPSW → re-download → different cable → disable security software. Mac IPSW location: ~/Library/iTunes/iPhone Software Updates/

If none of the above works, the issue is most likely physical hardware damage — a failing chip, corroded connector, or broken internal component. If you've tried everything above and the error keeps coming back, the problem is most likely physical — something broken inside the device that software can't fix. That's when it needs professional hands-on inspection.