Having an iPhone that randomly restarts can be frustrating. There are a few potential causes for this issue that are worth investigating.
Quick Overview of Main Causes
In most cases, an iPhone restarting by itself is caused by one of these factors:
- A software glitch or bug
- An app that is not responding properly
- Problems with iOS updates
- Too many apps running in the background
- Insufficient storage space on the device
- Overheating from processor strain
- Issues with RAM (memory)
- Hardware defects or damage
- Battery and power-related problems
Figuring out which one applies to your specific situation is key to resolving random restarts. The solutions may range from simple app troubleshooting to getting a battery replacement.
Software and App Issues
Problems with iOS system software or downloaded apps are among the most common triggers for iPhones restarting spontaneously. Here are some of the main software-related factors to look into:
Bugs in iOS
The core operating system that runs on iPhones – iOS – contains millions of lines of sophisticated code. Despite Apple’s extensive testing, bugs inevitably occur in iOS releases. Some bugs can cause stability issues that lead to random restarts and crashes.
Updating to the latest stable iOS version can often resolve bugs causing restarts. If you are already on the current update, try installing the latest beta release, which may contain undisclosed bug fixes.
Problematic Apps
Apps downloaded from the App Store can also be a source of instability if they are poorly programmed. A rogue app may use system resources incorrectly or have memory management issues, triggering device reboots.
Try troubleshooting by uninstalling any apps recently added before the restarting started. Check app reviews as well for reports of crashes. Removing problem apps often stops spontaneous restarts.
App Background Usage
Too many apps running constantly in the background can sometimes overload an iPhone’s memory and CPU cores. This app congestion can cause the device to become unresponsive and restart.
Go to Settings > General > Background App Refresh and switch off apps not needing constant background access. Also set seldom used apps to Manual refreshing only.
Updating and Syncing Issues
Failures occurring during app updates, iOS updates and iCloud syncing may require device reboots to recover from. If this coincides with when you notice random restarts, it points to software update processes as the trigger.
Make sure apps and iOS are updated properly and disable automatic updates temporarily if needed. Check that you have sufficient iCloud storage as well.
Jailbreaking Problems
Jailbreaking an iPhone gives root access to the operating system, but this can also lead to stability issues and crashes necessitating reboots. Avoid unauthorized iOS modifications that may be linked to restarting behavior.
Hardware Performance Factors
In some cases, random iPhone restarts stem from hardware problems rather than software glitches. Here is a closer look at potential hardware-related causes.
Insufficient Storage
iPhones require a certain percentage of the internal NAND flash storage to be free for smooth operation. If storage space gets too low, it can result in slowdowns, app crashes and spontaneous reboots.
Check Settings > General > iPhone Storage for available space. Offloading unused apps and files may stop storage-related restarts.
| Storage Used | Free Space Needed |
| 64GB | 5GB or more |
| 128GB | 10GB or more |
| 256GB | 20GB or more |
Overheating from Heavy Use
Using processor-intensive apps and games can heat up the iPhone’s components. Prolonged overheating triggers an automatic safety shut down and reboot to prevent hardware damage.
Avoid running intensive apps for very long. Also take steps like removing protective cases to improve airflow and passive cooling.
Old Battery Causing Shutdowns
If an iPhone’s battery has degraded below 80% of original capacity from age and charge cycles, it may trigger unexpected shutdowns requiring reboots.
Check battery health in Settings > Battery > Battery Health. Replace battery if capacity is below 80%. Turning off CPU-intensive features may help temporarily.
RAM Management Issues
Opening too many apps at once or system memory leaks can overwhelm the iPhone’s limited RAM (memory). The system may then freeze and spontaneously restart to clear memory.
Avoid opening more than 5 heavy apps simultaneously. Close background apps not being used. A device reboot clears temporary memory issues.
Logic Board Problems
The logic board contains the iPhone’s main processor and many other components. Short circuits, failed components and loose connections on the logic board can contribute to random crashes and restarts.
If no software fixes resolve the issue, it may require professional logic board diagnosis and microsoldering repairs.
Power and Battery Problems
Issues with power delivery and batteries are another set of common culprits for iPhones restarting spontaneously. These include:
Faulty Chargers and Cables
Damaged lightning cables and aftermarket chargers that don’t provide steady, regulated power can lead to unexpected restarts while charging. Use only Apple MFi certified cables and chargers.
Inspect cables for breaks or bent pins. Try different cables and chargers to isolate problems.
Charging Port Faults
Buildup of dirt and debris in the iPhone’s lightning port can prevent proper charging and data contacts. This may manifest as charging interruptions that lead to crashes and reboots.
Carefully clean out the lightning port using a wooden or plastic toothpick. Compressed air can also help dislodge particles.
Failing or Swollen Battery
An iPhone’s lithium-ion battery eventually degrades over repeated charge cycles, leading to reduced runtime. As batteries age and swell, they may trigger unexpected shutdowns with reboots.
Check battery health and performance. Swollen or failed batteries requiring replacement can cause spontaneous restarts.
Power Button Hardware Defects
Faulty power/sleep-wake buttons on some iPhone models can generate erratic signals causing the device to randomly power cycle and reboot.
A loose or sticking power button points to a hardware defect needing professional repair for replacement.
Troubleshooting Random Restarts
With many potential causes, a systematic process of elimination helps troubleshoot random iPhone restarts:
- Update iOS software and apps to latest stable versions
- Check iPhone storage space and free up space if needed
- Toggle off Background App Refresh for unused apps
- Delete any recently installed unstable apps
- Reset all device settings and test (no data loss)
- Inspect device battery health and charging components
- Try disabling certain location services and widgets
- Reset the device to factory defaults (will erase data)
- If hardware issue, take device to Apple Support for servicing
A step-by-step approach based on likely culprits makes it easier to stop random restarts and determine if a software fix or hardware repair is needed.
Preventing Future Random Restarts
To help minimize random restarts going forward:
- Avoid letting storage get critically full
- Only install apps from trusted developers
- Manage app background usage and terminate apps not being used
- Keep iOS and apps updated
- Use device cases to prevent overheating
- Replace battery if capacity drops excessively
- Avoid exposing device to moisture and physical damage
- Install iOS updates promptly to get bug fixes
Proactively monitoring these areas reduces the chances of system crashes leading to spontaneous reboots.
When to Seek Repairs
If an iPhone continues restarting randomly after trying common troubleshooting steps, it likely points to a hardware defect or component failure that requires repair:
- Battery replacement needed for swelled or degraded battery
- Charging port requires cleaning or replacement
- Logic board inspection for faults
- Power button replacement due to sticking or malfunction
- Damaged Lightning cable causing power issues
Third party repair shops can handle some issues like batteries and screens. More complex component-level logic board repairs may need Apple factory technicians.
Data Backup Before Service
Before taking an iPhone in for diagnostics or repairs due to random restarts:
- Back up important data and photos
- Log out of sensitive apps and accounts
- Encrypt device and backup
- Remove SIM card and memory card
Backing up key data provides peace of mind in case factory resets or component replacements are required during iPhone service.
Conclusion
Random and spontaneous iPhone restarts are often due to isolated software glitches or rogue apps. Updating iOS, deleting unstable apps and freeing up storage space can frequently solve the problem.
However, hardware issues like aging batteries, power delivery faults and logic board failures may also be at play. Carefully troubleshooting and diagnosing the root cause is key to stopping frustrating spontaneous reboots.
If software fixes do not work, take the iPhone to Apple support or a qualified repair shop. Getting professional repairs for any defective hardware causing the restarts will provide a permanent solution.