Were you trying to restore your iPhone or iTunes when you got an error message with the code -1?
Typically, performing a full restore isn’t something you want to do on a regular basis. It is difficult, takes up hours of your time, and can be very tedious to perform. When issues like this pop up on your computer and delay the process even further, a solution is made necessary.
The reason most people perform a full restore on their iPhone for iTunes is to solve some of the scarier software issues that can pop up at times. You might also do this right before selling your phone in order to wipe it clean so you don’t have to risk losing private information.
The problem with this is that if there is even a picobyte of data that is corrupted during the full restore process, you’re going to find a snake pit of issues opening up. The “-1 error” is a prime example of this, and it can be quite tricky, if not impossible to fix.
A Description of the Error Message and How it Appears
The error message on your screen right now should go something like this: “This iPhone could not be restored. An unknown error (-1) occurred.” It appears when you try to restore your iPhone or iPad using iTunes on your computer while the phone is connected to it.
The most common cause of this error appearing is that the baseband chip in the phone is corrupt. This is a hardware issue. However, it doesn’t mean that you should take your phone to the nearest Apple store or repair center. This could cost you a lot of money and you may not even get your phone back in the end. The reason you should wait is that in many cases, it is not a baseband issue causing the corruption.
Before you do this, try out some of the solutions listed here. Remember that the most common time for this error message to appear is at the end of the restore process, and not at the beginning. It happens during the final stages when new data is being written onto the baseband chip of your phone to finalize the restoration using iTunes.
How Do I Know This is a Hardware Issue?
Before you get started on working on the different -1 error fixes and solutions, you should check if it is actually a hardware issue that caused it. If you use the older iPhone 4 or 3G models, you can restore the phone using custom firmware. This is a rather complicated process that makes use of the redsn0w or sn0wbreeze mods. You will need to refer to a detailed guide on how to do this. Using these builds, your restoration should be easy. Once you gain access to your home screen using the custom build, go to your Settings, then tap on General > About > See IMEI.
With newer generations of iPhone like the 5, 5S, 5C, 6, 6S, 6+, 6S+, 4S, and 7 models, you can’t do the same thing. If you manage to get to your home screen, tap the (i) on the activation screen to view your IMEI. If there is no IMEI number being displayed, you are being plagued with a baseband or hardware issue, which means that the solutions here may not work. If your IMEI number still shows up, you should proceed.
Solutions to the Error -1 for iPhone
- Update your Operating System. Open up the Updates page on Windows or the Software Update page on Mac. Install all available updates so your OS is fully updated.
- Launch your iTunes application. Open up the options menu and update iTunes to the latest version. Make sure your internet connection is active and working.
- Deactivate your antivirus. One of the most common restrictions to the solutions here working is third-party antivirus software. This software’s firewall is likely to block data downloads to your device, which can damage your phone. Update your antivirus, then disable the protection until the restore process has been completed. Deactivate your computer’s firewalls as well.
- Disconnect all other peripherals. Take away any flash drives, external hard drives, printers, scanners, cameras and other USB devices. Keep your keyboard and mouse connected, then reconnect your iPhone. Restart your computer and try the restore again.
- Close iTunes and open it up again. Try to restore your iPhone one more time. If you are running a virtual computer application, close it. It can interfere with USB cable data transfers.
- Try restarting your computer and trying the restore again.
- Connect your iPhone to your computer. Start iTunes.
- Turn off your iPhone.
- Hold down the power button and home button at the same time for 10 seconds.
- Release the power button but keep holding the home button down till iTunes notifies you.
- Click on update/restore to begin the process in DFU mode.
- Try restoring the iPhone without your SIM card inside it. This is because certain faulty SIM cards can stop data from being sent to the baseband chip, which makes iTunes think the chip is corrupt. If the -1 error still appears, remove your SIM card and then try Solution #3 again.
- Download the most up to date version of iOS using your PC’s iTunes application. Hold down shift on Windows or Alt on Mac and click restore. Select the official firmware you downloaded manually and wait for the restore to begin.
Solution #6 – WARNING
Only try this if you know how to work with iPhone hardware. You could permanently destroy your iPhone.
- Heat the baseband chip or replace the dock connector. We do not recommend that you do this at home. Take your iPhone to a repair center and have a professional do this for you.
Solution #7 – DOWNLOAD iCAREPHONE, A FREE SOFTWARE
- Connect your iPhone to your computer.
- Select Repair Operating System in the menu.
- Download the official firmware from the Apple Support site.
- Choose a repair mode.
- Click Start.
Do not do this method if you are wary about using software other than the official iTunes application!
Troubleshooting for the Error -1 Fix Methods
Try these quick solutions out if your error -1 fix is giving you problems:
- Always have iTunes fully updated.
- Ensure the connecting cable is the official iPhone cable that is made for your model. Any third party after-market cables like OnFire will not work with your phone for the restore process.
- Go to this link and select your device, OS, and other factors, then download the firmware.
- Go to iTunes, click restore while holding down Shift or Alt, then point to the downloaded firmware.
- Use solution #3 to put the phone in DFU mode, then start the restore.
If you are still having problems with your iPhone’s restoration process, it is highly recommended that you do not engage in any hardware fixes. The last thing you need is to permanently damage your iPhone, after all. The -1 error should be easily fixed with the solutions above. If it is not, it may be the best choice for you to take your phone to an Apple store or a repair center. Good luck!