Galaxy S8 fast charging not working, won’t turn on, screen stays black, other issues

Starting late last year, there’s a small number of users who started reporting losing fast charging feature on their #GalaxyS8. For these unfortunate S8 users, the problem seemed to have coincidentally happened after installing an update. If you have the same experience in your S8, despite having taken great care of it — no physical damage, not wet — then keep reading. We also answer other related issues so hopefully you’ll find this post helpful.

If you are looking for solutions to your own #Android issue, you can contact us by using the link provided at the bottom of this page.

When describing your issue, please be as detailed as possible so we can easily pinpoint a relevant solution. If you can, kindly include the exact error messages you are getting to give us an idea where to start. If you have already tried some troubleshooting steps before emailing us, make sure to mention them so we can skip them in our answers.

Problem 1: Galaxy S8 fast charging not working

Hi! I was sent a TMobile S8 to replace an overheating S7. Everything was fine until about 5 to 6 weeks ago; the fast charger stopped working. I purchased new adapter cables. They worked for a few weeks and then both stopped working and would not even slow charge. I tried using the cables in the original adapter in a a different outlet and no charge. When I plugged the cables into the phone and the computer however, I got a slow charge but no fast charge. It is possible that the adapter is bad and I intend to go check this at a TMobile store and possibly do a soft reset. Â I have heard however, that recent security updates in October 2017 messed with the fast charging on both s8 and s8 plus models. Would this be something the TMobile store can help me with or is that a Samsung issue? I intend to get an external wireless fast charger in the meantime. Thank you! — Kristina Koutsoudas

Solution: Hi Kristina. We’re still monitoring this issue at this time. We’ve been made aware of this issue late last year after receiving anecdotal reports following the October update. Having checked other third party support sites, forums, and social networking websites, we would like to think this may be a firmware coding issue. This means that Samsung may have tweaked its Android code resulting to some S8 units being unable to fast charge anymore. It’s very difficult to know for sure though so we’ll leave it Samsung to acknowledge it at a later time.

What we know at this time is that this issue does not affect all Galaxy S8 devices. We both have S8 and S8 Plus in our lab and so far, their fast charging feature are working normally. It’s possible that this problem may only be happening to certain models. Keep in mind that not all Samsung Galaxy S8 devices use the same components from the same manufacturer. It is for this reason that some issues only occurs in certain “batches.” Because we don’t know a lot of things from your particular model, as well as from others who have a similar experience, it’s very challenging to identify any pattern in them.

At your level, these are the troubleshooting steps that you can do:

Make sure that fast cable charging is enabled

A basic thing to check first in this situation is the fast cable charging feature. Make sure that it’s enabled before doing any other troubleshooting. Here’s how:

  1. Open Settings app.
  2. Tap Battery.
  3. Tap Settings menu (three-dot icon).
  4. Tap Advanced settings.
  5. Move the slider for Fast cable charging option to the right.

Try fast charging while the phone or screen is off

Fast charging is supposed to work even when you’re using your S8

Recalibrate the battery

In many power- or boot-related cases, the problem is caused by a poorly calibrated operating system and battery. To ensure that Android and the battery work normally, be sure to calibrate both of them. If you haven’t tried doing it before, follow these steps:

  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 phone.
  5. Use your phone until it completely runs out of power again.
  6. Repeat steps 1-5.

Restart the phone to safe mode

There’s little chance an issue like this is caused by a third party app but nevertheless, be sure to boot your S8 to safe mode and observe how it charges. The idea behind this troubleshooting step is to see if something will change when your phone is on safe mode. It’s worth reminding our readers that safe mode is similar to regular boot mode, though the only difference is the lack of third party apps. While your S8 is in this mode, all third party apps will not run. If one of these apps is causing the fast charging issue, there should at least be a change, when you charge your phone in safe mode. To boot your phone to safe mode, follow these steps:

  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 while it’s on safe mode.

Perform a factory reset

Another good troubleshooting step that you can try in this situation is factory reset. This will restore all software settings back to their defaults. If a bug has developed after installing an update, app, or software update, there’s a chance factory reset may be able to fix the problem. If you haven’t tried doing a factory reset in your S8 before, follow these steps:

  1. Back up data on the internal memory. If you have signed into a Google account on the device, you have activated Anti-theft and will need your Google credentials to finish the Master reset.
  2. From the Home screen, swipe up on an empty spot to open the Apps tray.
  3. Tap Settings > Cloud and accounts.
  4. Tap Backup and restore.
  5. If desired, tap Back up my data to move the slider to ON or OFF.
  6. If desired, tap Restore to move the slider to ON or OFF.
  7. Tap the back button to the Settings menu and tap General Management > Reset > Factory data reset.
  8. Tap Reset device.
  9. If you have screen lock turned on, enter your credentials.
  10. Tap Continue.
  11. Tap Delete all.

Flash the stock firmware

Finally, the last software troubleshooting step that you can attempt is to return your phone’s operating system to its original state, that is, the version it came with when you first unboxed it. This is especially helpful if you’ve already installed the latest Android 7 version at this time. For example, if your S8 is now running Android version 7.1, you should try to reflash Android 7.0 and see if it works.

Keep in mind that flashing is basically modifying your system files. If you flash the wrong firmware version or tried an incorrect step, there’s a chance that you’ll brick your device. If you don’t know what flashing is or how to do it, consider yourself an Android newbie. Be sure to do more research about it.

If possible, you can ask Samsung to do it for you by bringing your phone to their service center.

T-Mobile stores, which are designed to sell and not solve, may not be able to fix this problem at all so just skip them and focus getting help from Samsung.

Problem 2: Galaxy S8 keeps freezing

My Samsung Galaxy S8 continues to freeze. I have spoken to the Tech coach on multiple occasions no one has ever effectively fix the problem. We did a factory reset on the phone and it continued to freeze. Finally , they have sent me a new phone and now the new phone is freezing as well. There are no new apps on my phone. Between me and the Tech coach people we have done everything in your troubleshooting guide. I don’t know what else to do I think Samsung should replace the device with a brand new one. Please advise and please contact me at your earliest convenience. — Islandbear

Solution: Hi Islandbear. That the same problem occurs even with a replacement phone is a clear indicator that it’s not a phone issue at all. There must be an app you installed in both phone that interferes with the operating system. To confirm, do another round of factory reset, and observe the phone for 24 hours. Make sure that you don’t install any new or old app during this time. If your phone works normally (no freezes) when there are no apps installed after a factory reset, that confirms our suspicion. To fix your issue, you must exert more effort in filtering what stuff you add in your phone. Remember, not all apps are created equal. You only have yourself to blame if your system continues to freeze after installing your apps. Make sure that you review whatever app or file you add in your phone. We can’t be more specific what this app might be so you’ll have to do the heavy lifting of identifying it.

Problem 3: Galaxy S8 won’t turn on, screen stays black

Hey. been needing help with my S8 but never looked into it until now seeing as I’ve had back up phones. But since one of my backups have done the same thing I figured I’d give it a whirl.

Okay. So, my S8 worked fine, perfectly fine and hadn’t even had it a full 4 months when it decided to shut off on me while i was asleep and hasn’t came on since then.  I plug it up to charge, doesnt display that its charging, the LED light doesnt even light up when plugged up to a charger.  I’m not too sure what that cause could be and I’m kinda tech savvy myself, always have been.  I havent stuck it to a charging pad yet to see if maybe its the charge port.  Its strange though because when it messed up I used my Note 3 that was my back up phone, and it started acting crazy as well…. powering off out of nowhere and taking forever to turn back on, until one day while i was asleep just not long ago it shut off and wont power back on either.  Also will not show that it’s charging, nor will any LED light come on while its plugged up.  HELP PLEASE. — Chelsie Simmerman

Solution: Hi Chelsie. There’s a few things that can cause the problem you’re having so you must narrow down the possible causes to identify it. These are the possible factors that may cause your phone to do what’s it’s doing right now:

  • it has a charging issue
  • charging cable or adapter may be bad
  • charging port may be broken
  • battery is damaged or dead
  • power management ICs are not working
  • other hardware malfunction

We don’t think there’s a screen issue here at all so we won’t touch that. You also did not indicate that your phone was physically impacted, dropped, or exposed to elements so the screen is most probably okay.

Let the phone charge for at least an hour before turning it on

For an issue like this, it’s important that you let the phone charge long enough to power the battery back on. To be on the safe side, let your S8 charge for 30 minutes before attempting to turn it back on.

Use another charging port and/or adapter

If you have another Samsung S8 or device, try to see if you can charge the phone using its USB cable and adapter. The current cable and adapter may be broken so your S8 may have simply run out of juice.

Charge your phone using a computer

Some Galaxy users were able to fix charging problems by connecting their device to a powered USB port of a computer. Make sure that you try it as well.

Inspect the charging port

There may be dirt or damaged pins in the charging port so make sure to check it using a magnifier. If you think there’s something out of the ordinary in the port, use a can of compressed air to clear it out. Do not stick anything in the port to avoid damaging the pins.

Use a wireless charger

While not a permanent fix in itself, using a wireless charger can be a good workaround to extend the serviceability of your S8. If your phone charges via a wireless pad but not via cable, that means there’s either an issue with the charging accessories (charging cable or adapter) or with the charging port.

Send the phone in

If your phone remains dead after doing all the suggestions above, there must be an internal problem with your device that needs to be addressed. Be sure to contact Samsung so you can have it repaired or replaced.