How-to Fix An unknown error (1603)

On March 6, 2011

How-to Fix An Unknown Error (1603) while updating iPhone firmware.

Unkonwn error (1603)

The iPhone “iPhone” could not be restored. An unknown error occurred (1603).

Fix 1603 Unknown Error by following these steps:

  1. Download iReb latest version

    iReb can fix 1600, 1601, 1602, 1603, 1604 error on iTunes.

  2. Run iReb
  3. iReb will kill (close) iTunes software and guide you how-to enter DFU mode.
  4. Follow the guide to enter DFU mode.
    If your device was already in DFU mode, you don’t need to do anything, because iReb will be searching for DFU of any connected device.

    iReb DFU helper

    When the device found in DFU mode, iReb will automatically start exploiting the iPhone and let you to restore custom firmware.

    iReb DFU helper

  5. Once done, Your device is now in a PWNED DFU mode state (black screen).
  6. Do not click OK until you have finished restore the custom firmware.

    iReb PWNED DFU state (black screen)

  7. You may now launch iTunes and do SHIFT + Restore, to restore the custom firmware.
  8. Done. The custom firmware has been installed on your device. You may either setup as new phone or restore from previous backup. You can close iReb when the firmware has been installed.