How to fix Galaxy S8 Plus that keeps showing moisture detected warning when off and charging

One of the annoying issues that affected many Galaxy users in the past was moisture detected issue. In this troubleshooting article, we answer a variation of this issue. One of our readers reported that his #GalaxyS8Plus keeps showing moisture detected warning only when it’s off and charging. We hope this post will help in fixing this problem.

Problem #1: How to fix a Galaxy S8 Plus that keeps getting moisture detected warning when turned off and charging

I have a Samsung Galaxy S8 Plus for about 9 months. about a week ago I started getting notifications that there was moisture in the charging port. This only happens when the phone is powered off. When the phone is on there is no issue charging the phone. I have clean the charging port and made sure it was dry. I can even start the phone well I’m getting the moisture notification and that it begins charging properly. 

Solution: Normally, moisture detected error only occurs when the system detects moisture or water in or near the charging port area. If what you’re saying about the error only occurring when charging the device powered off, then it’s most probably due to a software glitch. This means that the operating system may be getting incorrect parameters due to a bad app or software bug. To fix this problem, you need to do a set of troubleshooting steps. Make sure to follow our suggestions below.

Ensure that charging port is dry

Before you do any software troubleshooting, see to it that the charging port is indeed dry moisture-free. Water molecules normally evaporate on their own so try to hasten the process a bit by making sure the phone is positioned optimally. You can do that placing your device near an indirect heat source like a back of a TV or computer tower so it receives some gentle heat. Leave the phone in this position for at least 24 hours. You can also shake the phone vigorously to dislodge any water or moisture that might be hidden.

Avoid sticking something to the charging port or using a can of compressed air. The latter might push the water further inside, especially if your phone’s water resistance protection has been compromised.

Clear the cache partition

Clearing the cache partition is necessary in this case, especially if the issue started after doing an update. Sometimes, Android system cache may get corrupted after an update or for some other reasons. To ensure that your phone has good system cache, follow the steps below:

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 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 to highlight “wipe cache partition.”
7. Press the Power key to select.
8. Press the Volume down key to highlight “yes” and press the Power key to select.
9. When the wipe cache partition is complete, “Reboot system now” is highlighted.
10. Press the Power key to restart the device.

Observe and charge on Safe Mode

Another good troubleshooting step that you can do in this case is to check if the issue is due to one of your apps. Not all apps are built with the same skill and expertise so there’s always a chance of one causing problems or interfering with Android. To check if our suspicion is true, you want to boot the phone to safe mode. In this mode, no third party apps will be allowed to run so if your S8 Plus charges normally after you boot it to safe mode, you can bet one of the apps must be to blame.

To boot to safe mode:

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 and see what happens.

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 S8 is still problematic, repeat steps 1-4.

Install latest Android update

Some Galaxy users were able to fix moisture detected error in the past by simply installing an update. By default, your S8 is supposed to automatically download and install Android updates but if you changed this behavior, be sure to manually check under Settings > Software update.

Factory reset

Ultimately, you may need to resort to factory reset if all the suggestions above won’t work. Factory reset will erase all user data and return all software information back to their defaults. If the reason for the problem is due to an unknown software bug, factory reset might help. Here’s how to perform a factory reset on your S8 Plus:

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 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.

Problem #2: How to fix a Galaxy S8 with black screen of death (won’t turn on)

I have a Samsung Galaxy S8 that has the Black Screen of Death. I was able to get the screen to respond very slowly after a soft reset but when I tried to access factory reset I continually got an error that said the System UI was Unresponsive and gave me the choice to kill it or wait. I tried to wait repeatedly as I was slowly making progress, until it stopped entirely. I have tried Volume Down, Power button. Volume Up Power button. Volume Up Home and Power Button. But it won’t reboot or go into the menu. The phone will charge. The LED light still blinks for notifications and the phone occasionally makes notification noises. But the screen won’t come on and it won’t reboot. Sadly I’m a couple months away from being able to upgrade.

Solution: Your phone may have encountered an operating system error it can’t resolved by itself. Depending on what you did previously that led to this situation, there may or may not be a way to fix it. In this situation, there are only three suggestions that we can give you:

• cache partition wipe
• master reset
• flashing stock firmware to the device.

The first two options require that the phone boots to Recovery Mode while the third needs Odin or Download Mode. In order to access these modes, the phone must be turned off first. Pressing the button combinations without turning the phone off first won’t work.

To boot your S8 to Recovery Mode:

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 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. Try wiping the cache partition first. If that won’t work, do the factory reset.

To boot your S8 to Odin or Download Mode:

1. Turn off the device. This is important. If you can’t turn it off, you’ll never be able to boot to Odin 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 Down key and the Bixby key, then press and hold the Power key.
3. Wait until you see the Downloading screen.
4. Follow flashing procedure for your device.

IMPORTANT: Flashing is only recommended for advanced Android users. If you haven’t heard of the term, or if it’s your first time to do it, be sure to do the necessary research. Flashing can potentially harm the software environment of your device for good so be ready to accept the risk that you might lose the phone if you fail. Use Google to look for a good guide to flash your phone.

Problem #3: Galaxy S8 freezing and battery level drains very fast

S8 starred freezing a couple of weeks ago and this became more frequent. To resolve I would perform a soft restart (power and vol down) which worked fine until a week ago, once it restarted the battery power would go down to 1%. Now today I charged it fully but it would power down after 2 mins of use. This then got progressively shorter (the time on b4 power down). I plugged it back in and performed an update as suggested but now it won’t start up at all. I get the Samsung S8 screen, then spark then dull flashing Samsung then off. I tried one of your suggestions of wiping the cache and have made sure no apps are running in the background . Any ideas what might be going on??

The phone is now used by my daughter so no calls or messages, just apps mostly Musicly and camera/videos. It was my old phone. Charlotte Lee

Solution: Your phone’s battery might have a bug causing the phone to shut off prematurely. To see if you can fix it, try to recalibrate the OS and the battery. Here’s how:

1. 1. Drain the battery completely. This means using your device until it powers down by its own and the battery level reads 0%.
   2. Charge the phone until it reaches 100%. Be sure to use original charging equipment for your device and let it charge up completely. Do not unplug your device for at least two more hours and also don’t use it while charging. 
   3. After the elapsed time, unplug your device. 
   4. Restart the device.
   5. Use your phone until it completely runs out of power again.
   6. Repeat steps 1-5.

You can also factory reset the phone to return all its software information back to defaults. If the reason for the problem is a software issue, factory reset should work. Follow the steps above on how to do it.

Should no software troubleshooting will fix the problem, you can assume bad hardware is to blame. Bring the phone to Samsung for repair or replacement.

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