What to do if Galaxy S8 turns off due to overheating and won’t turn on

Electronic devices may sometimes get hot while in normal operation so manufacturers like Samsung adds a built-in mechanism to minimize damage to the system due to overheating. This mechanism can sometimes be interpreted as a problem by some users, like what one Galaxy S8 user reports below. If you have a similar situation on your own S8, learn what to do below.

Problem: Galaxy S8 turns off due to overheating and wont’ turn on

My Galaxy S8 device suddenly turned off while I was using it and was on charging (30% battery). I did feel it was overheating but there was no warning message. I have tried doing all the troubleshooting methods on this site (Forced Reboot and Booting in Recovery Mode) but nothing seems to work. I have plugged the phone into the charger, there is no light but the phone seems to be heating up. What can I do now?

Solution: Samsung Galaxy devices like your S8 are designed to power down after internal temperature reaches a certain level. Too much heat inside a cramped, poorly-ventilated space inside your phone can severely damage components. Samsung wants to limit this from happening and one effective way to do that is to shut the system down. ideally, this should also be a reminder for a user to allow the device to cool off.

Why your Galaxy S8 won’t turn on

Because your S8 was working normally before shutting down, we assume that there’s nothing wrong with it at all. If you tried to charge and turn on the phone immediately after shutting down on its own, the device may not power up at all. You must allow it to cool off for at least 30 minutes before charging and turning it back on. Remember, as long as its heat sensor still notices that there’s high temperature inside, the phone may refuse to power on. In some cases, a user may be able to turn the device on but it shuts down immediately after. The best thing that you can do now is leave the phone in room temperature for 30 minutes. After, charge it for another 30 minutes before turning it on.

What if the phone still refuses to power back on?

If your device becomes unresponsive and won’t turn on at all after following the suggestions above, you can do the troubleshooting steps below.

Use another charging cable and adapter

One of the common reasons for charging issues is a defect in charging cable or adapter being used. To check if this is the case, try to charge your S8 using another set of accessories. As much as possible, try to stick with official Samsung accessories and avoid third party ones.

Charge thru a computer

Some Galaxy S8 devices that refuse to charge using standard accessories may charge again after plugging them in to a computer. If you haven’t tried this simple trick, be sure not to skip it.

Wipe the cache partition or perform master reset

Any of these two options can only be done in Recovery Mode. Try to see if you can restart the phone to Recovery Mode with these steps:

  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).

If your S8 boots to Recovery Mode successfully, try to wipe the cache partition first. Here’s how:

  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 cache partition’.
  5. Press Power button to select.
  6. Press the Volume down key until ‘yes’ is highlighted and press the Power button.
  7. When the wipe cache partition is complete, “Reboot system now” is highlighted.
  8. Press the Power key to restart the device.

Should nothing work after wiping the cache partition, consider reverting all software settings to their defaults by doing a master reset.

  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.

Boot to Download Mode

If your S8 won’t boot to Recovery Mode at all, or if nothing works after wiping the cache partition or master reset, try to restart the device to Download Mode. Like Recovery Mode, this one is a separate software environment from Android. If Android Operating System has encountered a but preventing it from booting up, it won’t necessarily affect Download Mode as it’s independent of Android. As long as there’s no hardware malfunction or other deeper programming issues, you should be able to boot the device to Download Mode. This mode is important for Samsung technicians as this is where they go to when flashing or installing the stock firmware. If you can boot the phone to this mode, there’s a chance an Android OS bug is behind the trouble.

To boot a Galaxy S8 to 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 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 Down key and the Bixby key, then press and hold the Power key.
  3. You’ll know if you’re on Download Mode when you see a screen that says “Downloading….”

Even if your S8 boots to Download Mode successfully, this doesn’t mean that the problem goes away. However, this only goes to show that the problem has something to do with Android. To fix it, flashing of stock Samsung firmware may be necessary. If you don’t know how to do that, we suggest that you let Samsung do it for you.

Get professional help

If your S8 won’t boot up to Download Mode at all, or if remains dead or unresponsive, there might be a hardware issue behind it. In this case, you want to let Samsung know about the trouble so they can help you with repair or replacement.