| How To Fix an iPhone 14 That Randomly Restarts | |
|---|---|
| Device | iPhone 14, iPhone 14 Plus |
| Affects part(s) | Main Logic Board |
| Needs equipment | Screwdrivers, known good parts, spudger |
| Difficulty | ◉◌◌◌ Easy |
| Type | Part replacement |
Problem description
There are many reasons that could cause an iPhone 14 and iPhone 14 Plus to randomly restart every few minutes.
For the iPhone 14 series, there are some sensors within the parts of the phone that are required to be plugged in & detected. Otherwise, the phone restarts on its own.
If certain parts are unplugged, you may also face restarting problems.
The most common for iPhone 14 series are:
- Back Glass/Wireless Charging Flex- This is the flex that is attached to the Back Glass. It can damaged during a drop or screen replacement
- Proximity Flex -This is the flex that is attached to the screen. It can easily be liquid damaged or torn during a screen replacement.
- Charging Port Flex - This is the flex towards the bottom of the phone. It is easily damaged with a drop & the back glass is breaks. Or when someone has repaired the back glass.
Symptoms
- After a back glass repair, the iPhone will restart on its own every few minutes
- After a hard drop, the iPhone will restart every 3 minutes.
- After a screen repair, the iPhone will bootloop every 3 minutes
- The iPhone will reboot randomly when using it.
- The iPhone will seem to freeze and restart every 2-5 minutes.
Solution
Diagnostic Steps
Before you start blindly replacing parts, it's important to try to confirm what is causing the restarting issue by reviewing the Panic Log file. This is a file that is generated by the Operating System, to document the fault causing the restart.
To find the panic log on the device, go to Settings-> Privacy-> Analytics & Improvements-> Analytics Data-> Scroll down to the files starting with "panic-full..." & click on the most recent dated file.
Then you'll want to scan through the text for keywords that may point you to the cause.
For this model, look for where it says "SMC PANIC - ASSERTION FAILED" ... "Sensor Array" .. "0x...."
If you see:
- 0x400000 - it's the Wireless Charging Flex (Back Glass)
- Make sure it's plugged in & the flex is not torn
- Check that there's no liquid damaged, or that it's defective
- Test with OEM or Premium. Aftermarket Flexes have a high defect rate
- Diode mode the FPC connectors for any faults
- Could be a sandwich issue
- 0x100000 - it's the Charging Port Flex
- 0x500000 - Check the taptic engine as well as the charging port flex
- Make sure this flex is plugged in
- Check that no flex is torn, liquid damaged, defective
- Test with OEM or Premium. Aftermarket Flexes have a high defect rate
- Diode mode the FPC connectors for any faults
- Could be a sandwich issue
- 0x200000 - it's the Proximity Flex Cable
- Make sure this flex is plugged in
- Check that no flex is torn, liquid damaged, defective
- Test with OEM or Premium. Aftermarket Flexes have a high defect rate
- Diode mode the FPC connectors for any faults
- 0x500000 - it's a communication problem with the battery
- the battery has a communication issue while charging
- restarts every 3min30sec
- test with another battery
- check diode values on battery connector on the motherboard
- 0x600000 - it's wireless Charging flex + proximity Flex Cable
- check with original known good flex
- both must be connected to the motherboard
Alternatively, you can use a tool like the iDevice Panic Log Analyzer, which will download the panic logs from the device & display them on the PC & give you suggestions to possible solutions. It makes it easier to browse the panic log file.
Also check out www.PanicFull.com which allows you to upload the panic log file & have it analyzed for free.
Both of these tools just give suggestions, which aren't always correct, as there is no official solution list from Apple. So many solutions are just suggestions based on hearsay, rumors or just guesses.
For situations where you don't see the above examples, you'll have to read through the top portion of the panic log & try to decipher what could be the root cause. Look for keywords you may recognize.
Repair Steps
When troubleshooting these issues, make sure the flexes listed above are all plugged in. You cannot test for restart problems by unplugging the flex cables.
It is also a good idea to keep known good parts on your bench, for testing only.
There are reports of even NEW flexes being bad. So you must keep known good flexes on hand at all times, so you don't waste your time troubleshooting with possibly bad flexes.
Always make sure to replace the appropriate flex with an OEM or Premium parts. Don't use aftermarket parts.
In scenarios where you have the appropriate flexes plugged in (listed above), but it still restarts, then you either have:
- Bad or damaged flex
- Low quality aftermarket flex
- Other flex cables that are Liquid Damaged
Please note: You MUST have the required flex cables plugged in. Otherwise, it WILL restart. You cannot troubleshoot this step by unplugging the bad flex.