Most IPSW installation errors come down to a handful of causes: a corrupted download, outdated iTunes or Finder, a connection that dropped mid-restore, or the wrong file for your device. This guide maps the common error codes to their actual causes and the fixes that work, with links to our dedicated pages for each code.
Quick Reference: What Each Error Code Means
| Error Code | Common Cause | Quick Fix |
|---|---|---|
| 3, 11, 12, 13, 14 | Hardware/connection fault | Check USB connection |
| 9, 9006 | Network connection issues | Check internet connection |
| 17, 1638, 3014 | Security software interference | Disable security software |
| 21, 53, 2003 | USB connection problems | Try different USB port/cable |
| 39, 40 | iTunes/Finder communication issues | Restart computer and device |
| 1004, 1013 | Network timeout | Check network settings |
| 1600, 1601, 1602 | Device in wrong mode | Enter correct recovery mode |
| 1671 | iTunes connection timeout | Update iTunes/Finder |
| 2005 | Communication error | Check USB cable/port |
| 3194 | Unsigned iOS version | Use currently signed IPSW |
Find your code below for the full fix. Each code also has its own page (for example Error 14 or Error 4013) with deeper detail.
Before You Retry: 60-Second Checklist
Most errors disappear before they happen if these four things are true:
- The IPSW file is verified: size matches the listed size, checksum compared, downloaded from a trusted source
- Software is current: latest iTunes (Windows) or macOS version
- Connection is solid: original Apple cable, plugged directly into the computer (no hubs), stable internet
- You have a fresh backup: restores erase the device, so never retry a failing install without one
Fixes by Error Code
3, 11, 12, 13, 14: Hardware or Connection Fault
- Try a different USB port; on desktops, use a rear port
- Swap the cable for an original Apple one (cables fail constantly)
- Inspect the device’s charging port for lint or debris
- Restart both computer and device
- Try a different computer; if the error follows the device, it’s hardware
9, 9006: Network Failure
These mean the download or verification was interrupted:
- Test your connection; pause other downloads and streaming
- Disable VPN and proxy (the #1 cause of this error)
- Try a wired connection or a different network
- If your antivirus filters traffic, disable it temporarily
17, 1638, 3014: Security Software Interference
Security software sees firmware flashing as suspicious behavior:
- Temporarily disable antivirus/third-party firewalls
- Add iTunes/Finder to the software’s exception list instead of leaving protection off permanently
- Re-enable everything once the install finishes
21, 53, 2003: USB Communication Problems
- Original Apple cable, direct connection, different port
- Clean the device’s charging port
- Restart the computer with the device already connected
- If errors persist across cables and ports, suspect the device’s port hardware
39, 40: iTunes/Finder Communication Errors
- Quit and relaunch iTunes/Finder, then restart the computer
- Update iTunes or macOS
- On the device: Reset All Settings (Settings > General > Transfer or Reset iPhone > Reset). Settings only; data survives.
1004, 1013: Network Timeout
Same family as Error 9: check the connection, drop the VPN, use wired internet, and try off-peak hours. These are timing failures, not file failures.
1600, 1601, 1602: Wrong Device Mode
The device wasn’t in the state iTunes/Finder expected:
- Re-enter Recovery Mode with the correct button combo for your model
- If Recovery Mode keeps failing, use DFU Mode instead; it bypasses more of the software stack
3194: Unsigned iOS Version
The file you’re installing is no longer signed by Apple. There is no consumer-level workaround:
- Check the signing status page for versions that still work
- Download a signed version and install that
- Historical note: SHSH blobs once bypassed this on legacy devices, but that era ended years ago; no modern iPhone or iPad accepts unsigned firmware
When Recovery Isn’t Enough: DFU Mode
If standard restores keep failing, DFU Mode replaces the firmware at a deeper level. The screen stays black in DFU; an Apple logo means the timing slipped and you should retry.
iPhone 8 and newer:
- Press and quickly release Volume Up
- Press and quickly release Volume Down
- Press and hold the Side button for 10 seconds
- While still holding Side, press and hold Volume Down for 5 seconds
- Release Side, but keep holding Volume Down for 10 more seconds
iPhone 7 / 7 Plus:
- Press and hold the Side button and Volume Down together for 8 seconds
- Release the Side button, but keep holding Volume Down for 10 more seconds
iPhone 6s and earlier:
- Press and hold the Home button and Sleep/Wake button together for 8 seconds
- Release the Sleep/Wake button, but keep holding Home for 10 more seconds
From DFU, hold Shift (Windows) or Option (Mac), click Restore, and select your verified IPSW. Full instructions: Recovery/DFU guide.
A note on third-party flashing tools (3uTools and similar): Apple’s own software handles everything they do, with none of the risk. Stick with Finder/iTunes.
When to Stop and Get Help
Contact Apple Support or an authorized service provider when:
- The same error survives every fix above, across different cables, ports, and computers
- The device shows physical damage, water exposure, or won’t power on at all
- It’s stuck in a boot loop or recovery loop after multiple restore attempts
- Activation Lock appears on a device without matching credentials
Those patterns point to hardware (baseband, storage, or logic board), and no amount of retrying changes that.