What to do if Galaxy S8 won’t turn on or if screen fails to power back on [troubleshooting guide]

This troubleshooting article will give you advise on what you need to do when your #GalaxyS8 seems dead and won’t power on. The two cases mentioned below are some of the extreme cases of an S8 failing to turn back on after a disastrous event that results to physical damage. Based on the descriptions of the users below, their devices had clearly seen better days as both had clear signs of a broken screen.

Keep in mind that our blog can only help Android owners with possible software problems. The two cases below hardly qualifies for a software-related situation so don’t be dismayed if you’ll not find hardware troubleshooting or diagnostics in this post. We don’t do them, and we don’t intend to. Hardware repair are better left for technicians who can physically examine the device. If you’re looking for hardware remedies, try looking for videos in YouTube, or visit other blogs.

Problem 1: Galaxy S8 is dead and screen stays black, won’t turn on

My phone is completely dead. Went to bed with the phone working as usual I plugged it into the original wall charger and fell asleep. When I woke up the phone was dead. There was no LED lights showing it was charging. I tried different chargers but still no response. Soft reset and hard reset no luck; still dead. I think it might be a battery problem. The phone is only 6 months old so it is still under warranty but I cracked the screen so would need to get that replaced before Samsung or my carrier would look at it. That cost is around $500 which I do not have. If the problem is the battery I can replace it myself but would like some opinions on what could be the problem. Thank You. — Vuletic-93

Solution: Hi Vuletic-93. Based on how you describe your device and the problem, it’s looks like your S8 is having difficulty turning back on (if it still can). There’s a number of possible reasons why this is so:

  • bad charging cable or adapter (hence you are unable to charge the battery, hence a “dead” phone)
  • broken charging port (hence you are unable to charge the battery, hence a “dead” phone)
  • battery has stopped working (or receiving charge)
  • Power Management Integrated Circuit (PMIC) is broken or malfunctioning
  • there’s an unknown motherboard issue that affected critical components (probably related to the reason why the screen was cracked?)
  • software glitch

We’re here for the last one — possible software glitch. Sure you can try to see if it’s a charging cable or adapter issue by using another known working USB cable and adapter but we doubt this is where the issue lies. It’s either there’s a serious software error in the system, or there’s a hardware failure behind it.

To see if your S8 has an unknown Android problem, you can try to isolate Android by booting your device to either Odin Mode or Recovery Mode. These two modes are independent of Android and as long as hardware is working, your phone should be able to boot to any of them. Odin Mode is used by Samsung technicians in servicing devices. The same is true for Recovery Mode. Each of them are designed to work even if Android won’t load at all. If you can load your S8 to Odin Mode or Recovery Mode, then there’s a chance that the issue can’t be fixed on your level. Otherwise, you’re doomed.

To boot your S8 Recovery Mode:

  1. Charge your S8 for at least 30 seconds. Do this even if you’re not getting the LED charging indicator. Also, if possible, try using another known working charging cable and adapter.
  2. Turn off the device, if it’s not yet.
  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).

In Recovery Mode, there are two things that you can do — clear the cache partition and master/factory reset. If your S8 boots to Recovery, make sure to do either or both of these options to fix it.

To boot your S8 Odin/Download Mode:

  1. Charge your S8 for at least 30 seconds. Do this even if you’re not getting the LED charging indicator. Also, if possible, try using another known working charging cable and adapter.
  2. Turn off the device, if it’s not yet.
  3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  4. After the Samsung phone name logo, you will see a screen with a warning sign. Proceed ahead by pressing the Volume Up button.

In Odin Mode, there’s only one thing that you can do — flash the firmware or bootloader. We won’t recommend that you do this unless you are unable to boot the device to Recovery Mode as well. In this situation, you really have no other choice but to try flashing stock firmware to the device. This is not a guaranteed solution so may still end up with the ultimate solution — sending the phone in.

Problem #2: Galaxy S8 screen is flashing green and won’t charge

Screen is black, phone is on, has flashed blue and red solid, and now flashing green and not charging. battery had died and I went to turn on and saw Samsung across screen and then went black and I placed on the charger. Soft reset is not working, phone also overheats periodically during soft reset process at the moment. Samsung s8 so have to unglue back to remove battery. The software is the most up to date, possibly Oreo. — Kristie

Solution: Hi Kristie. Your issue may appear similar to Vuletic-93’s above but there’s actually one important difference — yours still powers on. What that means for you is that the issue may be user-fixable. Unless your S8 has been physically damaged and the screen is messed up, booting it to Recovery Mode or Download Mode should fix it. Refer to our suggestions for Vuletic-93 above.

We can’t help you if your S8’s hardware has been permanently damaged for reasons only you know. If you need additional support other than booting to Recovery Mode or Download Mode and doing each of their follow on procedures (such as clearing the cache, doing a master reset, or flashing), you should consult Samsung first. If Samsung repair is out of the question, let a professional service the hardware for you.