Samsung Galaxy Note 9 keeps rebooting after the Android 9 Pie update

When a premium smartphone like the Samsung Galaxy Note 9 keeps rebooting by itself, you can almost expect it to be a firmware issue. That has always been the case even with previous Galaxy models. The thing is, some Note 9 owners started complaining about the problem after they updated their phones to the recent Android 9 Pie update.

Don’t worry though as this problem can be fixed easily. In this post, I will help you troubleshoot your Note 9 that keeps rebooting on its own. We will consider every possibility and be thorough in our troubleshooting so that we can determine what the problem really is and hopefully fix it. If you’re one of the owners of this device and are currently being bugged by the same issue, continue reading as this article may be able to help you.

Before we proceed, if you’re looking for a solution to a problem with your phone, try to browse through our Galaxy Note 9 Help Guides page to see if we support your device. If your phone is in the list of our supported devices, then go to the troubleshooting page and look for similar problems. Feel free to use our solutions and workarounds.

Troubleshooting Galaxy Note 9 that keeps rebooting

Performance issues are really pesky but they’re not necessarily that hard to fix provided that the firmware hasn’t been modified in any way. If you’ve rooted your Note 9 and installed a custom ROM or UI and you’re having this problem, then re-flash the stock firmware and then start from there. But assuming that the firmware is still intact and not modified, try the following procedures.

First solution: Isolate that problem immediately

It is obvious that the usual forced restart won’t work on this problem so the first thing that I want you to do if your phone keeps rebooting by itself is to restart it in safe mode. This will temporarily disable all third-party applications. It is important that you do this procedure because it’s always possible that the cause of the problem is a third-party. Here’s how you start your phone in safe mode:

  1. Press and hold the Power key until options show.
  2. Tap and hold the Power off option until it changes into Safe Mode.
  3. Tap the Safe mode icon to restart your device.
  4. Once the reboot is successful, you should see ‘Safe mode’ at the lower-left corner of the screen.

Continue using your phone while it’s in safe mode to see if it still keeps rebooting on its own. If the problem is fixed, then it’s confirmed that one or some of your apps is causing the problem. You just have to determine the culprit and uninstall it. Here’s how you do that…

  1. Restart your phone normal to boot into standard mode.
  2. Remember the apps you installed about the time when the phone starts to reboot by itself.
  3. Once you already have an app in mind, swipe down from the top of the screen to pull the notification panel down.
  4. Tap the Settings icon on the upper-right corner.
  5. Scroll to and then tap Apps.
  6. Find and tap suspected app.
  7. Tap Storage.
  8. Touch Clear data and tap OK to confirm.
  9. Tap the back key once and then touch Uninstall.
  10. Confirm that you want to remove the app from your phone.

You may have to uninstall more than one app to get the problem sorted out.

On the other hand, if your phone still reboots by itself even in safe mode, then the problem could be with the firmware. Move on to the next procedure.

ALSO READ: What to do if your Samsung Galaxy Note 9 won’t charge?

Second solution: Reset all settings

There was one instance that I enabled the developer mode in my phone and changed the settings that made sense to me, although I didn’t really understand their functions. After doing so, my phone became so sluggish, started to heat so fast and randomly restarted by itself. I couldn’t remember which setting I change so what I did was reset all settings. This could just the case with your phone so it’s best to do this procedure as well. Here’s how…

  1. Swipe down from the top of the screen to pull the notification panel down.
  2. Tap the Settings icon on the upper-right corner.
  3. Scroll to and tap General management.
  4. Touch Reset.
  5. Tap Reset settings.
  6. Tap the Reset settings button.
  7. If prompted, enter your PIN, Password or Pattern.
  8. Finally, tap Reset.

After the reset, try to see if your Note 9 still keeps rebooting by itself. If it still does, then move on to the next procedure.

ALSO READ: How to fix Samsung Galaxy Note 9 that won’t send pictures through text?

Third solution: Delete the system cache so it will be replaced

The next thing you need to do is troubleshoot the first if your phone still keeps rebooting after the first two procedures failed to fix the problem. One of the most effective procedures is to wipe the cache partition which deletes the system cache. But you’re not just deleting the cache, you’re actually replacing it with a new one and here’s how you do it:

  1. Turn off the device.
  2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  3. When the Galaxy Note 9 logo shows, release all three keys.
  4. Your Galaxy Note 9 will continue to boot up into the Recovery Mode. Once you see a black screen with blue and yellow texts, proceed to the next step.
  5. Press the Volume down key several times to highlight wipe cache partition.
  6. Press Power key to select.
  7. Press the Volume down key to highlight yes, them and press the Power key to select.
  8. When the wipe cache partition is complete, Reboot system now is highlighted.
  9. Press the Power key to restart the device.

Your phone will take a little longer to reboot after this as the cache is being rebuilt. Once your phone has successfully rebooted, try to use it normally and see if it still keeps rebooting. If it still does, then it’s time for the ultimate solution.

ALSO READ: How to fix Samsung Galaxy Note 9 that won’t turn on?

Fourth solution: Backup your files and reset your phone

A master reset will surely fix this problem but need to make sure that you’ve made a backup or copy of your important files especially ones that are stored in your phone’s internal storage as they will be deleted. After the backup, make sure to remove both your Google and Samsung accounts so that you won’t be locked out after the reset. If everything is in order, then follow these steps to reset your device and fix the problem:

  1. Turn off the device.
  2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  3. When the Galaxy Note 9 logo shows, release all three keys.
  4. Your Galaxy Note 9 will continue to boot up into the Recovery Mode. Once you see a black screen with blue and yellow texts, proceed to the next step.
  5. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
  6. Press Power button to select.
  7. Press the Volume down key until ‘Yes’ is highlighted.
  8. Press Power button to select and start the master reset.
  9. When the master reset is complete, ‘Reboot system now’ is highlighted.
  10. Press the Power key to restart the device.

I hope that we’ve been able to help you fix your Galaxy Note 9 that keeps rebooting on its own. We would appreciate it if you helped us spread the word so please share this post if you found it helpful. Thank you so much for reading!

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