Check these first
Do not assume the cause from the symptom alone. First determine whether the issue affects the whole phone, one app, one connection, or one accessory. Work from low-impact checks toward recovery or repair.
- Prepare a compatible Mac or Windows computer and reliable cable
- Update Finder, Apple Devices, or iTunes
- Confirm backups, Apple Account access, and two-factor recovery methods
Narrow down the cause
| Scope of the issue | Where to check next |
|---|---|
| Only one app is affected | Check app permissions, updates, storage, cache, and reinstall options |
| The whole phone is affected | Check restart, system updates, free storage, and system settings |
| Other devices have the same issue | Check the network, service, charger, or accessory |
| The issue began after a drop or liquid exposure | Avoid repeated power or charging attempts and contact official support |
See the troubleshooting flow
Safe step-by-step process
Complete one step at a time and test after each change. Do not change several settings at once.
- 1Update the computer and Apple device software and connect to stable internet.
- 2Connect the iPhone and use the model-specific button sequence until the Recovery mode screen appears.
- 3When the computer reports an iPhone problem, record any error number and exact wording.
- 4Choose Update first because it normally reinstalls iOS without intentionally erasing user data.
- 5If the download takes long enough for the iPhone to leave Recovery mode, wait for the download to finish and enter the mode again.
- 6Restore erases the iPhone. Use it only if Update fails and only after verifying the backup and account recovery.
Actions to avoid
- Saving encrypted-backup passwords on a shared computer
- Choosing Restore without reading the difference
- Starting recovery with an unstable cable or USB connection
Prevent the issue from returning
- Keep an encrypted computer backup or iCloud backup current
- Keep Apple Account access and trusted phone numbers updated
Frequently asked questions
What if my screen looks different?
Menu names and locations vary by OS, manufacturer, model, region, and software version. Use the Settings search field and check the manufacturer guide for your exact model.
When should I stop troubleshooting?
Stop as soon as the issue is fixed. Change one setting at a time so you can identify what solved the problem and reverse it if necessary.
What should I do if the issue remains?
Record how to reproduce it, verify your backup, and contact the manufacturer, carrier, or app provider most closely related to the problem.