Galaxy S8 keeps freezing and rebooting on its own, screen not turning on

Today’s troubleshooting article is about the #GalaxyS8 that shows symptoms of hardware malfunction — random freezing and rebooting. The two cases mentioned below will most likely end up with repair but all is not lost in all similar cases though. Even if your S8 has been showing the symptoms mentioned here, there’s still a chance that its cause may be software in nature so there’s still something that you can do about it. Find out what it is that you can do before eventually sending your device in.

Problem #1: Galaxy S8 freezing and rebooting on its own

Randomly freezing and rebooting while using the phone. This morning (after I plugged it in the charger last night) it freezed sometime during the night.. it didn’t reboot. I rebooted it with the volume down and power button. I already tryed wiping the cache, factory reset, factory reset from the touchwiz menu. It all didn’t work.. I bought the phone second hand and this problem already started the 1st day. Can this be a hardware problem? Or do I still have something to try software wise. Hope you can help me. Greetings. — Mark (Netherlands)

Solution: Hi Mark. Buying pre-owned smartphones is usually a hit-and-miss. Sometimes, if you’re lucky enough, you may get a perfectly working device while at other times, it’s the complete opposite. If your S8 was already freezing and randomly rebooting right after buying it, that should have been enough to tell you that something’s wrong with it. Just like with most issues with Android devices, your problem may be caused by bad hardware or by a software or app glitch. To know where the problem lie, there’s only one thing that we can suggest, since you’ve already tried a factory reset. This suggestion is safe mode.

Restarting to safe mode is a necessary troubleshooting step and in fact, the only thing that you can try to confirm whether or not your S8 has a hardware problem. When on safe mode, no third party apps will be allowed to run so if your S8 keeps on freezing or rebooting because a bad app was re-installed after you factory reset the device, it should work normally. In other words, you want to know if a third party app is to blame. If it’s not, then you’re not in luck.

To restart your S8 to safe mode:

  • Turn the device off.
  • Press and hold the Power key past the model name screen.
  • When “SAMSUNG” appears on the screen, release the Power key.
  • Immediately after releasing the Power key, press and hold the Volume down key.
  • Continue to hold the Volume down key until the device finishes restarting.
  • Safe mode will display in the bottom left corner of the screen.
  • Release the Volume down key when you see Safe Mode.
  • Let the phone run in safe mode for 24 hours.

Remember, safe mode is not a solution. It’s a tool to help you diagnose whether or not a bad app is interfering with the system. If your S8 will work normally throughout the observation period, that’s an indication that our suspicion is correct. To know what app is causing the trouble, you need to spend time uninstalling apps individually. Make sure that after you delete an app, you start the phone normally again and check for the problem. If the issue returns, you want to proceed uninstalling the next app. Do this cycle until you’ve identified the bad application. This is a tedious process but it’s the only way to know the problematic app.

However, if your S8 continues to freeze or reboot randomly even when it’s on safe mode, that’s your cue to go ahead and have it repaired. There must be a hardware issue causing it shutdown or perform poorly so you may need to have its logic board replaced.

Problem 2: What to do if Galaxy S8 screen turns black and won’t boot up after a factory reset

Hi..my Galaxy S8 one day went black screen. It wouldn’t power up normally. Did a soft reboot..and came up with big pic of green robot and lots of different colour text top left.. nothing happened. Tried again..this time wouldnt even reboot. Assumed phone was dead ( no use anymore). Even tried charging..nothing happened at all. Went to bed.. out of one last attempt..plugged charger in again…battery power symbol appeared this time. Fully charged. Managed to do a reboot this time.Was stupidly slow and kept freezing. Decided to transfer files to my pc. Was working ok then just switched off again. Same again.. wouldn’t do anything for a whole day. Then tried again in morning..powered up very slowly. Decided to do a factory wipe. Did so. It still freezes…crashes..switches off randomly for hours at a time. Its completely volatile with crazy actions. Everytime it does manage to reboot..it shows blue text in the top left corner..think it says soft reboot or safe reboot..i can’t remember. Im close to throwing it against the wall!! It’s never been wet..or too hot.. The phone has had full updates so i assume it’s got the latest operating system whatever that may be? — Zannapooch

Solution: Hi Zannapooch. We’ve seen similar symptoms you’re describing here with devices having bad batteries or those that got wet. Unfortunately, there’s not much that you can do about the issue since a factory reset did not help at all. At most, you can follow our suggestion for Mark above by restarting the device to safe mode. Other than that, you’re probably looking at a probable repair scenario. If your S8 is still under warranty, or if you didn’t void its warranty by physically breaking it or exposing it to water, then Samsung may examine and repair your S8 for free. Otherwise, you’re really going to invest in its repair.