How to Fix iTunes Error 1600 When Restoring iPhone

By ErrorFix · Updated October 20, 2026 · 8 min read

What error 1600 means

Error 1600 appears in iTunes on Windows or Finder on a Mac while you are restoring an iPhone. The dialog says the iPhone could not be restored and that an unknown error occurred (1600), and the phone is left waiting for a restore that never began properly — often showing the cable-and-computer screen or a completely black display. Your data is not confirmed gone, but the restore cannot proceed until the underlying mode or firmware problem is corrected.

The code itself gives the clue. Error 1600 sits in the 1600 range of iTunes errors, a family tied to the firmware-flash phase of a restore. Where later codes in the family fail mid-flash, 1600 usually means the flash never started: the phone is in recovery mode when DFU mode is required, the firmware file on the computer is corrupted or was never meant for this restore, or the computer-side software is too old to run the DFU handshake. Retrying the same restore from the same mode fails the same way until the mode is fixed.

The fix is almost always on the computer side and within your control. Enter DFU mode with the correct button sequence for your iPhone model, clean up the USB connection, update iTunes, disable security software for the attempt, and download a fresh firmware file — and error 1600 almost always resolves at one of those steps.

Common causes

• Phone not in DFU mode: the phone sits in recovery mode while the restore expects DFU, so the firmware flash never starts.
• Corrupted or invalid firmware file: a half-downloaded IPSW, or a custom or unsigned firmware image, fails validation before flashing.
• Outdated iTunes or macOS: old software mishandles the DFU restore handshake and aborts with 1600.
• Bad USB connection: a worn or uncertified cable, a USB hub, or an unstable port corrupts the low-level transfer.
• Security software interference: antivirus or firewall tools interrupt the traffic between the computer and the phone in DFU mode.
• Stale hosts-file entry: a gs.apple.com redirect left over from jailbreak or downgrade tools breaks firmware verification.

How to fix error 1600 — step by step

Follow these in order. Error 1600 is a flash-phase failure that happens before flashing starts, so the first step — entering real DFU mode — clears most cases on its own. The later steps clean up the computer side, and the DFU restore with fresh firmware at the end is the fallback that almost always works.

1. Put the iPhone into proper DFU mode. Error 1600 almost always means the phone is not in the restore mode the firmware expects, so the single most reliable fix is entering DFU mode correctly. On iPhone 8 and later: connect the phone to the computer, press and quickly release Volume Up, press and quickly release Volume Down, then press and hold the Side button until the screen goes black — then hold Side and Volume Down together for five seconds, release Side but keep holding Volume Down until the computer says it found a device in recovery. The screen stays black; that is how you know DFU mode worked. On iPhone 7 or 7 Plus: hold the Side button and Volume Down together for eight seconds, release Side, and keep holding Volume Down until the computer detects the phone. On iPhone 6s and earlier: hold the Home and Sleep buttons together for eight seconds, release Sleep, and keep holding Home. Once the computer sees the phone with a black screen, click Restore and let the fresh firmware install.
2. Clean up the USB chain. Even in DFU mode, a dirty USB connection can break the firmware stream and keep error 1600 appearing. Use a genuine Apple cable or a certified MFi cable and plug it directly into a USB port on the computer itself — no hubs, docks, or keyboard pass-throughs. Try a different port, preferably a USB 2.0 port, and unplug every other USB device for the duration of the restore. Then start the restore again.
3. Update iTunes, Finder, and the computer's software. Old iTunes builds and old macOS versions mishandle the DFU restore handshake that error 1600 is tied to. In classic iTunes on Windows, click Help at the top of the window and choose Check for Updates; if you use Apple's modern apps, open the Microsoft Store, go to Library, and update Apple Music and Apple Devices. On a Mac, restores run through Finder, so install pending macOS updates from System Settings, General, Software Update. Restart the computer after updating, then retry the DFU restore.
4. Temporarily disable security software. Antivirus and firewall programs often interfere with the low-level traffic between the computer and a phone in DFU mode, and error 1600 is a common symptom. On Windows, open Windows Security, go to Virus and threat protection, and pause real-time protection for the duration of the restore; also check the firewall rules and make sure Apple Mobile Device Service is allowed. If you run a third-party suite, disable its active shields. Turn everything back on the moment the restore finishes.
5. Delete the cached firmware and download a fresh copy. A half-downloaded or corrupted IPSW file on the computer can keep producing error 1600 even when DFU mode is entered correctly. Force a fresh download by deleting the cached firmware: on Windows, remove the IPSW files from %AppData%\Apple Computer\iTunes\iPhone Software Updates; on a Mac, delete them from ~/Library/iTunes/iPhone Software Updates. Then put the iPhone back into DFU mode, click Restore, and let the computer download a clean firmware image. This erases the phone, so keep an iCloud or computer backup ready to restore from afterward.
6. Try a different computer and check the hosts file. If error 1600 survives DFU mode, fresh USB, updated software, and a new firmware file, the machine itself may be the problem — try the restore on a second computer with iTunes or Finder current. On your own computer, also check the hosts file: a gs.apple.com redirect left over from jailbreak or downgrade tools can send Apple's verification to the wrong place. On Windows, open Notepad as an administrator and open C:\Windows\System32\drivers\etc\hosts; on a Mac, open Terminal and edit /etc/hosts. Delete or comment out any line mentioning gs.apple.com, save, restart, and retry the restore.

Did this fix it? Quick checklist

• iPhone entered DFU mode correctly: black screen, computer detects the device
• Genuine or certified cable, direct USB port, everything else unplugged
• iTunes or macOS updated, security software and VPN disabled for the attempt
• Restore completes in DFU mode with freshly downloaded firmware — no error 1600

If error 1600 survives DFU mode, a clean USB chain, updated software, fresh firmware, and a second computer, the phone's own flash hardware may be at fault. Book an Apple Store or authorized service appointment and mention error 1600 so they know the restore is failing before the flash begins.