iPhone keeps restarting: what to check before repair

For an iPhone that keeps restarting, try a working charger, then check for updates if you can access the operating system. If the Apple logo stays for several minutes without a progress bar, Apple says recovery mode might be needed to restore it. Service might be needed if you can't update or restore it with recovery mode.

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By Tim KatzgrauPublished Nov 4, 20264 min read

Key takeaways

Start with a charger you know works.²
Check for software updates if the phone stays on long enough to use it.²
Choosing Restore erases all your data.¹
A battery below 80% capacity needs battery service.²

What should I check if my iPhone keeps turning on and off?

Start with a charger you know works. Try a force restart too. If the phone stays on long enough to use it, check for software updates. Lint can get packed into the charging port each time you plug the cable in.²

Check the cable's fit
Trapped lint can keep the cable from fitting well. So can other debris.²
Clear any trapped debris
Use a toothpick or another probe that doesn't conduct electricity.²

Don't charge or leave the phone in hot places for long periods, including in direct sun.³

Why does my iPhone keep showing the Apple logo and turning off?

An Apple logo that stays for several minutes with no progress bar means you might need recovery mode to restore the phone. A computer that doesn't recognize it, or reports it's in recovery mode, is another sign. So is the "Connect to computer" screen.¹

To start Apple's recovery process, connect the phone to your computer with a cable and keep it connected. The button steps include holding the side button until the "Connect to computer" screen appears.¹

Why does my iPhone keep turning off and restarting?

Restarts can happen when your phone can't communicate with parts inside it, such as the battery, charging port or their connections. The port's internal cable can fail too. Faults can involve the power button cable. The camera flash cable or its connector on the main circuit board can fail too.²

If the other checks haven't worked, failed or damaged parts on the main circuit board may be causing the restarts. Have a repair shop check which part has failed.²

A battery can fail to supply enough power. That can cause an unexpected shutdown. Battery Health can tell you if you need a new battery.³

Will restoring my iPhone erase my data?

Restore erases all your data. It also reinstalls the phone's software. In Apple's recovery steps, you choose Restore when the computer offers Update or Restore, then wait while the software downloads. Once that process ends, set up your phone again.¹

If the download takes more than 15 minutes, your phone might leave the "Connect to computer" screen before it finishes.¹

When should you take your iPhone to a shop?

Your iPhone might need service if you can't update or restore it with recovery mode, Apple says. A stuck or broken button that prevents recovery mode can also mean it needs service. Battery capacity below 80% calls for battery service.^{1, 2}

Fix	Price	Shop or DIY
A different cable or adapter you already have	Free	DIY: try a working charger
Cleaning the charging port	Free	DIY: clear trapped debris
A force restart	Free	DIY: a troubleshooting step
A software update	Free	DIY: if the phone stays on
Avoiding prolonged heat	Free	DIY: Apple's battery care advice
Restore using a computer	Free	DIY: Apple's recovery process
Battery service	Ask a shop for a quote	Shop: capacity below the service threshold
Charging port or internal cable repair	Ask a shop for a quote	Shop: possible internal faults
Power button or camera flash cable repair	Ask a shop for a quote	Shop: possible internal cable faults
Circuit board repair	Ask a shop for a quote	Shop: small parts may have failed
Service for a stuck or broken button	Ask a shop for a quote	Shop: button prevents recovery mode
Service after recovery mode fails	Ask a shop for a quote	Shop: can't update or restore

Questions

Can cold weather affect the battery's power?

A battery's peak power might decrease. Cold weather and a low charge can raise battery impedance for a while, which can make it harder to supply enough power. High impedance also means a larger voltage drop while your phone draws power.³

Why did my battery health reading change?

Battery health readings on iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max can change through recalibration. The change addresses wrong estimates for some users. It's part of iOS 14.5 and later, and covers both how much charge the battery holds and the peak power it can supply.³

What should I check if my phone might have gotten wet?

If there's a chance your phone got wet, check its liquid damage indicator. The sticker sits under the display. Use the repair guide for your model to open it. If you find signs of liquid, iFixit's iPhone Liquid Damage Guide might help.²