Galaxy S8 Plus fast cable charging won’t work, won’t boot up, stuck in boot loop

Like any previous Galaxy models, the new #GalaxyS8 and #GalaxyS8+ are not immune from common issues like not charging properly, failure to power on or boot up. If you’re looking for a solution on how to fix any of these issues in your own S8 device, you’re in luck. Continue reading and make sure to follow our suggestions.

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 Plus fast cable charging won’t work

Hi. i bought my Samsung Galaxy S8 plus from second hand. Everything is working well and has been for the few months that I have it. However there is one problem that my device wont fast charge even though it is enabled. I was given the original charger and everything that goes with it. Sometimes it wont even show that it is charging at all. This is happening for about 4 days now. I have to wait 6h 15m to be fully charged.

I bought a completely new charger but it did not help so I tried different combinations with the wires and adaptors with my original charger that came with the device and plugging it to a different socket around the house but still no difference… Hope my details were clear for you to understand and help me out as I honestly give up now, after basically trying everything even rebooting, restarting and uninstalling some apps. — Kristian

Solution: Hi Kristian. Samsung’s fast charging feature requires a number of things in order to work. These stuff includes:

  • the original Samsung adapter
  • the original Samsung USB cable
  • a good working charging port
  • a good working software

Use only the stock Samsung fast charger and stock Samsung USB cable

Fast charging in your S8 requires a special adapter (the original Samsung fast charger that originally comes with the box). Using a different Samsung adapter for a non-S8 model (although we can confirm S7’s fast charger still works) may not allow fast charging at all. Keep in mind that fast charging feature is managed by your phone’s power IC as well as the chip in special adapter itself. If there’s a wrong value or input from the adapter, your phone will use regular charging feature instead of the fast charging one. The same logic is the reason why it’s equally important that you only use Samsung’s original USB cable. Not all USB cables are created equal and Samsung own cable is the one’s that’s validated to work with your device’s power IC. using a third party USB cable may generate heat that can cause incorrect current or resistance values while charging.

Enable fast charging in Settings menu

Fast charging feature can be enabled or disabled anytime. Make sure that you turn it on by doing the following steps:

  1. Open Settings app.
  2. Tap Device maintenance.
  3. Tap Battery.
  4. Tap Settings icon at the top (three-dot icon).
  5. Select Advanced settings.
  6. Enable Fast cable charging by moving the slider to the right.

Don’t use the phone while fast charging

Samsung’s fast charging feature on the Galaxy S8 won’t work if the screen is on. If you’re trying to use the device while charging it as well, don’t expect fast charging to kick in. To charge your S8 faster, turn the device off.

Check the charging port

Of course, making sure that your phone’s charging port is important as well but since there’s no direct and easy way to test it out, you’ll have to assume that it’s working … for now. You want to  temporarily skip it in your troubleshooting considerations and instead proceed to factory reset.

Since you mentioned that your phone even appears to not charge at all, there’s a chance that the issue may lie with the charging port. The most that you can do to check it though is to perform a visual inspection. With the help of a magnifier, check the inside of the port to see if there’s dirt, lint, or foreign object that might block the cable from making contact with metal pins. Also, be alert for any bent or deformed pins.

If you think the charging port is dirty, you can use a can of compressed air to blow away the dirt inside. Avoid sticking anything inside to prevent damaging the pins.

Return all software settings to factory defaults

Factory reset is a necessary troubleshooting step to eliminate any possible software bug affecting the charging function of your phone. If you haven’t tried it yet, here’s how it’s done:

  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.

Use a wireless fast charger

While not a permanent solution, using a wireless charger and enabling fast wireless charging under Settings should be a good remedy. Fast wireless charging is still way slower than fast cable charging though so you’ll still notice a significant difference in terms of charging session times.

Send the phone in

Getting a pre-owned device can sometimes be risky as the original owner may have damaged it, or there may already be an existing issue with it. If the steps above won’t help in fixing the problem, then we suggest that you send the phone in to Samsung so the charging port can be examined or repaired. If that’s not where the problem lies, a full motherboard replacement may be necessary.

Problem 2: Galaxy S8 Plus won’t boot up, stuck in boot loop

Last night my Samsung S8+ turned off out of nowhere. When I went to turn it back on, it would load the Samsung logo screen followed by a blue screen with Android on it and it says, “installing system updates” will appear for a half of a second then shut back down. So I thought my phone had died so I hooked it up to the charger and now it keeps doing those same two screens on loop. I tried the vol down and power button and it keeps doing the same thing on loop. Any help you can give me will be better then what Verizon or Samsung could do. Thank you. — Mike

Solution: Hi Mike. An issue like this usually happens when a user tampers with the software (rooting or flashing). In other cases, Galaxy devices may fail to load the operating system after installing an update. To fix the issue, there are three possible solutions that you can try.

Wipe the cache partition

Your phone’s storage device is divided into partitions in order to compartmentalize data. Sometimes, the partition that keeps downloaded contents, update installer packages, and app installers called cache partition may have corrupted contents. This can lead to problems ranging from minor annoyances to boot up problems. To ensure that your phone’s cache partition is fresh, you can clear it. Hopefully, doing so would fix the problem you’re currently having. Here’s how it’s done:

  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 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.

Perform a master reset

Master reset, also known as factory reset, is another way of fixing this type of problem. Since you can’t do the regular factory reset via Settings (as detailed above), you should try to boot the phone to Recovery Mode first before you can wipe it clean. If you haven’t tried it yet, here’s how:

  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. 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 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.

Reflash the bootloader (Recovery) and/firmware

If this problem occurred after you attempted to root or flash the device, we suggest that you flash the bootloader back to stock first, then flash the original firmware as well. In most cases, it fixes boot loop problems.

Flashing instructions can vary depending on the device. Make sure that you follow a good guide on how to do it in your particular phone model.

Below are the general steps (may not be the exact steps for your S8) on how to flash a Samsung bootloader. Flashing the firmware should be mostly similar except for a few things.

  1. Look for the correct firmware for your phone model and download it. Make sure that you select the right one. It should be the same exact firmware that ran previously on your device. We assume that you list down the firmware version somewhere. If you did not take note of it before, there’s a chance that you may pick the wrong one. As you may know now, using an incorrect firmware can cause complications so good luck with that.
  2. Let’s now say that you have identified the correct firmware. You then want to download it to your computer. The firmware file should have a bunch of files in it like AP_, BL_, CSC_, etc.
  3. Look for the file that starts with a label BL; this should be the corresponding bootloader file for this firmware. Once you’ve identified the bootloader file, copy it to your computer’s desktop or to any other folder that you can easily access.
  4. Proceed with the rest of the flashing procedure using the Odin program.
  5. In Odin, click on the BL tab and make sure to use the bootloader file you’ve identified earlier.
  6. Now, make sure that the “Device Added” status and its “ID:COM box” has turned blue before hitting the START button. This will initiate the flashing of your phone’s bootloader.
  7. Restart the phone once the procedure is finished.