How to fix a Galaxy S9 that turns off on its own and won’t power back on [troubleshooting guide]

The #GalaxyS9 was released just weeks ago but already, some users have been contacting us about their devices failing to power on after turning off by themselves. While we’re not surprised by this issue as it’s one of the perennial problems for Samsung Galaxy devices, we did not expect to hear S9 owners experiencing them this soon. If you are one of the unlucky few to have encountered this problem, be sure to follow our suggestions below.

Check charging accessories for damage

Before you try any of our solutions below, you should ensure that the charging accessories you’re using are in order. We know that the issue in this post assumes there may be a fault with the phone but making sure that charging accessories are working is still an important consideration. You don’t want to do drastic troubleshooting steps like factory reset when the real issue lies on a bad charging cable or adapter. Basically, what you want to do is to check if there’s visible damage to the USB cable and adapter. We also presume that you’re using the original USB cable and adapter throughout this time. If you weren’t consider getting the original Samsung charging accessories and see if that will help power the phone back on

Solution #1: Charge for at least 30 minutes

If you’ve been using the original Samsung USB cable and adapter all along and you’re positive that both are working fine (by using it to charge another device perhaps, or by using another known working set of charging accessories), then make sure that your S9 has not simply lost battery power. You can do that by letting it charge for some time. For troubleshooting purposes, you want to charge your S9 for at least 30 minutes. This should be enough to recharge a fully depleted battery to about 40%.

Solution #2: Use a wireless charger

There’s a chance that your S9’s charging port may be problematic. While you can physically check the port itself for obvious signs of damage, under-the-hood failures may be hard to detect by an average user. To see if your phone’s charging port is damaged or not working, you can use a wireless charger to charge the phone. In this situation, we suggest that you let your phone charge for at least an hour. If your S9 remains unresponsive, you can then try to force restart your S9.

Solution #3: Force restart your S9

Majority of Samsung Galaxy devices that fail to power on turn out to be not dead devices at all but are actually frozen system. In other words, the devices have simply got stuck for some reason and users were unable to do anything about them. To know if your own S9 has simply frozen or became unresponsive, you can try to unfreeze it by doing the steps below:

Press and hold the Volume Down button first and don’t release it.
While holding it down, press and hold the Power key.
Keep both keys held down for 10 seconds or more.

You should only attempt to force restart your device after charging it for at least 30 minutes (or an hour when using a wireless charger).

Solution #4: Boot to safe mode

Although it’s rare to see a smartphone disabled or blocked by an app from booting Android, it’s not impossible. If your S9 coincidentally failed to boot up after installing an app, you should not eliminate the possibility that said app may be to blame. To check, you want to boot your device to safe mode. Remember, when your S9 is in safe mode, only third party apps will be blocked from running. If you’ll be able to power on your phone to safe mode but not in normal or regular mode, that’s a telltale sign of possible bad app in the system.

To restart your S9 to safe mode, follow these steps:

Turn the device off.
Press and hold the Power key past the model name screen appearing on the screen.
When SAMSUNG appears on the screen, release the Power key.
Immediately after releasing the Power key, press and hold the Volume down key.
Continue to hold the Volume down key until the device finishes restarting.
When Safe mode appears in the bottom left corner of the screen, release the Volume down key.
While in Safe mode, you can now uninstall apps that are causing a problem.

Solution #5: Access alternate boot modes

In some cases, there may be an unknown Android bug that prevents it from working properly causing the system to regularly freeze, or even not power back on at all. To see if your problem is Android-related, you can boot the device to other software environment — Recovery Mode and Odin Mode. Both of these modes don’t need Android to work so if your S9 will be able to start to any one of them, you clearly have a problem with the operating system. Below are the steps how to start your S9 to any one of them.

How to boot your S9 to Recovery Mode

Turn off the device if it’s still on at this time. If you can’t turn it off normally using the Power button. You’ll have to wait until the battery is drained. After that, you’ll have to charge it before doing the steps below.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).

How to boot your S9 to Odin or Download Mode

Turn off the device if it’s still on at this time. If you can’t turn it off normally using the Power button. You’ll have to wait until the battery is drained. After that, you’ll have to charge it before doing the steps below.
When ready, press and hold the Power, Bixby and Volume Down buttons at the same time
Continue holding these three buttons down until it boots into the special blue screen
Press the Volume Up button to bypass the screen and boot into Download Mode

Remember, if your S9 will power on and start to any of these modes, that means you have an operating system problem. To fix the problem, you can either wipe the cache partition or perform a master reset.

Solution #6: Cache partition wipe

Wiping the cache partition is only applicable if you are able to start your S9 to Recovery Mode. This procedure will take care of possible corrupted system cache that may be causing the problem. Here’s how to do it:

Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the Android logo displays, release all three keys.
An ‘Installing system update’ message will show for 30 – 60 seconds before the Android system recovery menu options appear.
Press the Volume down key several times to highlight wipe cache partition.
Press Power key to select.
Press the Volume down key to highlight yes, them and press the Power key to select.
When the wipe cache partition is complete, Reboot system now is highlighted.
Press the Power key to restart the device.

Solution #7: Wipe the phone thru Factory reset

Like the cache partition wipe procedure, factory reset or master reset can only be performed if you can manage to boot the device to Recovery. This will revert all settings back to their defaults and erase all personal data you might have on your phone. This means that you’ll lose unsaved files after doing it. To master reset your S9, follow these steps:

Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
Press the Volume down key several times to highlight “wipe data / factory reset.
Press Power button to select.
Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
Press Power button to select and start the master reset.
When the master reset is complete, “Reboot system now” is highlighted.
Press the Power key to restart the device.

Solution #8: Contact Samsung support

Ideally, your S9 should already be back in working order at this time but if it’s still unresponsive and won’t turn on after doing all the steps above, you can assume there’s a hardware malfunctioning causing it. This means that the problem is most probably not fixable at your level. To resolve the problem, we suggest that you contact Samsung so they can help you fix it.