Galaxy S8 Plus won’t turn on unless plugged in, fast charging not working properly

There are many Galaxy S8 Plus users asking for help regarding their device not turning on or no longer fast charging. In this post, we address both issues. See what you can about them below.

Problem: Galaxy S8 Plus won’t turn on unless plugged in, fast charging randomly stops

I use a Samsung Galaxy S8+. For the past few weeks, I have observed the following challenges / issues while using my phone:

  1. When I connect the charger to charge, it sometimes displays “slow charging” and at other times, it shows “fast charging”
  2. Sometimes, when am on a call, the person am talking to normally have some sound distortions during the course of the call.
  3. The major issue is that, my phone will go off on its own, even when it is fully charged, and while not come on except it is plugged to power and then switched on. After this, it will stay on and work normally for another 1 – 2 hours and then go off on it own; and I have to repeat the above process again. This happens even when the battery is fully charged and the phone also indicates that the battery is charged. Kindly help if you can.

Solution: Let’s answer each of the concerns individually.

Issue 1: When I connect the charger to charge, it sometimes displays “slow charging” and at other times, it shows “fast charging.”


First of all, you want to make sure that fast charging is enabled all the time. You can do that by going under Settings > Device Maintenance > Battery > More icon at the upper right > Advanced settings.

Secondly, you want to check the charging port. See if there’s any visible damage to the port, or if there’s dirt or foreign object inside. Pocket lint or dirt may block the cable during charging resulting to improper charge. If possible, try to inspect the port using a magnifying tool. If you don’t have that tool and you suspect that there’s dirt inside, use a can of compressed air to clean it out. DO NOT stick anything inside to avoid damaging the system.

Lastly, you want to know if the problem is caused by a bad charging cable or adapter. Find a known working cable and adapter and use it to charge your S8 Plus. Preferably, you only want to use official S8 or S8 Plus accessories to avoid encountering incompatibility issues.

 

Issue 2: Sometimes, when am on a call, the person am talking to normally have some sound distortions during the course of the call.

Are you sure this is not a speaker issue? Does your phone make distorted sounds even when you’re not on a call? If yes, then you need to have your speakers checked by Samsung.

If the speaker of your S8 appears fine when off calls, there’s a big chance that the problem is outside your control. It may be network-generated. There may be a problem with either your network or that of your contact. Try to narrow down the factors by observing calls from other users from other networks. If you think it only occurs when on call from one particular contact, it may be due to network problems on his or her end. There’s nothing much that you can do about that but you can tell the person involved so he or she can inform the carrier.

 

Issue 3: The major issue is that, my phone will go off on its own, even when it is fully charged, and while not come on except it is plugged to power and then switched on. After this, it will stay on and work normally for another 1 – 2 hours and then go off on it own; and I have to repeat the above process again. This happens even when the battery is fully charged and the phone also indicates that the battery is charged.

This looks like a battery issue. Try to calibrate the battery with these steps and see what happens. If the problem goes away after recalibrating, then fine. If it stays, you seriously have to contact Samsung for repair or replacement. It also means that the first issue is related to this one.

For reference, here are the exact steps on how to calibrate:

  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.

Restore device’s software to defaults

All the issues you mention here may have one single reason so it’s good if you can wipe the phone and return all software setup to their factory state. This is the best way for you to know whether or not there’s a software bug behind them.

  1. Create a backup of your personal data such as photos, videos, documents, etc.
  2. Turn off the device.
  3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  4. 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).
  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 — delete all user data’ 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.
  11. Let the phone run for 24 hours without adding any apps.

Get Samsung help

As a general rule, if nothing works after a factory reset, the phone must be sent to Samsung. We can’t see any reason why you would not do that if factory reset won’t fix anything. If that’s the case, there must be a hardware problem causing your issue. It’s most probably related to the phone’s Power Management function or battery. To know for sure, a Samsung tech will need to examine the phone physically.