How to fix Galaxy S9 charging issue: only charges via computer or car charger

There’s been a growing number of Galaxy S9 users asking us for help regarding power and charging issues so this one’s for them. As usual, the cases included below are taken from letters we receive. All power issues usually have the same general troubleshooting guideline so our suggestions should work even if there are slightly different circumstances.

Problem #1: How to fix Galaxy S9 stuck in boot loop issue: won’t turn on or boot to Recovery Mode

When we put the phone charger into the phone, the phone just goes into the Samsung Galaxy S9+ secured by Knox and powered by Android screen. After that it turns off turns on again and does the same thing over and over until it stucks on this Samsung S9+ secured by nox screen. We cant even turn it off. The safe mode doesn’t work. The reset doesn’t work. If we hold down the volume down key and power key it just restarts and goes into the screen again and it turns off and on again. The only key combination that works is bixby key volume down and power key. When we do that we get into the download custom os interface. We can’t access recovery mode or anything. 

Solution: In majority of cases like the one you have, the cause is most likely software tampering — failed rooting or flashing. Some few cases of this issue occurred following a legit OTA update. If you did any of these, you have two options at your disposal — flashing and getting support from Samsung.

Flashing

If your S9 became stuck in boot loop after playing around or tampering with the official software, flashing stock firmware to the device may help. The good thing is that the device still boots to Download or Odin Mode so there’s a fair chance that you can do it successfully. Make sure that you follow a good guide in flashing the device this time.

Get support from Samsung

If you never did root or flashed custom or unofficial ROM, and if the issue started after over-the-air update, we suggest that you talk to your carrier or Samsung for assistance. If you are familiar with Android and can follow flashing instructions, you can also try to flash stock firmware to the device to resolve the issue. We highly recommend though that you go through Samsung’s repair program to be on the safe side. Remember, flashing is inherently risky and can damage the software or phone’s partition for good if not done correctly. To prevent voiding the manufacturer warranty, let a trained professional help you by sending the phone in.

Problem #2: How to fix Galaxy S9 charging issue: only charges via computer or car charger

My Samsung S9 will only charge when connected to my computer’s USB port or in my car, and only when it decides to. I have tried other wall mounted chargers and different plugs, but nothing works. I had taken it to the phone shop to show them and my battery was charged at 99% and when they plugged it in with their charger and with mine, it charged straight away, so they told me to come back when it wouldn’t charge again. After that visit I left my phone battery run out completely, and then it was out of service for 24hours before it decided to charge connected to my computer.

Solution: This problem might be caused by a bad third party app, software bug, or hardware malfunction. To check whether the issue can be fixed on your level, follow our suggestions below.

Clear the cache partition

This is an important first step. For an intermittent issue like yours, there’s a chance that a bad system cache has something to do with it. To fix the problem, we suggest that you clear the cache partition. Doing so will refresh the system cache and the entire system after a restart. Here’s how to do it:

1. Turn off the device. This is important. If you can’t turn it off, you’ll never be able to boot to Recovery Mode. If you are not able to shut the device off regularly via the Power button, wait until the phone’s battery is drained. Then, charge the phone for 30 minutes before booting to Recovery Mode.
2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
3. When the Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
4. Press the Volume down key to highlight “wipe cache partition.”
5. Press the Power key to select.
6. Press the Volume down key to highlight “yes” and press the Power key to select.
7. When the wipe cache partition is complete, “Reboot system now” is highlighted.
8. Press the Power key to restart the device.

Check for bad third party apps

Another possible reason for the problem is an app, more specifically, the ones you added. To check, you want to restart the phone to safe mode. Safe mode will prevent all third party apps from running. Because only preinstalled apps will be running in this state, you’ll know if the issue is caused by an app if it won’t occur. In other words, if your S9 charges normally in this mode, you can bet an app is to blame.

1. Turn the device off.
2. Press and hold the Power key past the model name screen.
3. When “SAMSUNG” appears on the screen, release the Power key.
4. Immediately after releasing the Power key, press and hold the Volume down key.
5. Continue to hold the Volume down key until the device finishes restarting.
6. Safe mode will display in the bottom left corner of the screen.
7. Release the Volume down key when you see Safe Mode.
8. Charge the phone using official charging accessories.

If you think there’s a bad app issue, you need to determine which one is responsible. To identify which of your apps is causing the trouble, you should boot the phone back to safe mode and follow these steps:

1. Boot to safe mode.
2. Check for the problem.
3. Once you’ve confirmed that a third party app is to blame, you can start uninstalling apps individually. We suggest that you begin with the most recent ones you added.
4. After you uninstall an app, restart the phone to normal mode and check for the problem.
5. If your S9 is still problematic, repeat steps 1-4.

Return software settings to defaults (factory reset)

The ultimate test that you can do is factory reset. This will help you know if there’s a software or operating system bug causing the trouble. By wiping the phone, you are effectively returning all its software back to their defaults. In its factory state, your device is not supposed to have any charging problems so this will help you know if the problem is software-related or not.

If the phone still fails to charge normally, even right after a factory reset and when there are no other apps installed, that means bad hardware is to blame.

To factory reset your S9:

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 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).
4. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
5. Press Power button to select.
6. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
7. Press Power button to select and start the master reset.
8. When the master reset is complete, ‘Reboot system now’ is highlighted.
9. Press the Power key to restart the device.

Repair

If the continues to exhibit charging problems after it’s been factory reset, it may have a charging port issue, or something in its motherboard is not working right. Make sure that you let Samsung check the gadget so they can repair or replace it.

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