Bootloop issue is usually a result of unofficial software modification but in a case mentioned below, it appears that a Galaxy S8 simply crashed or turned off on its own. After a restart attempt, the phone no longer turns on properly and is now stuck in this bootloop situation. If you have a similar situation, check out our suggestions below.
Problem: Galaxy S8 crashes and stops booting up
Hello. This is a long read. My Galaxy S8 is stuck in a boot loop. I looked at your forum and tried your suggestions but none of them worked. I’ll start from the beginning so I can provide as much detail as possible. I was in a video call when my phone shut off. At first a white circle would pop up on screen with a lightning bolt and that would keep flashing. I’m guessing it was because it was plugged in. When I unplugged it, the model screen saying “SAMSUNG GALAXY S8 powered by android” would appear and the phone would vibrate once as if booting up then it would go black and repeat. When I plugged it in it would have show the screen with the white circle and the lightning bolt and then would go to the normal charge screen showing what battery percent it was at. I tried all the manual reset options that was recommended, none worked. So I left it running to allow it to run out of power. When it ran out I plugged it in. The charge screen did not appear this time, but it still looped the same way when trying to turn it on. So I tried to do a manual reset again. it didnt work, but now the boot loop is slightly different. Now the same model screen as before would appear, but after that a blue update screen appears with the android logo, a spinning circle of arrows, and text that said “installing system update”. This screen would only pop up for half a second before looping. I believe none of the resets work because it never makes it to the “SAMSUNG” logo screen as described in the reboot instructions. I did make sure the power button is not stuck pressed in. I have not tried to flash boot it because it seems complex and I could not find a good guide as to how to do it. If I can get help in any way, that would be much appreciated. I do not want to mail my phone to samsung to get it fixed, but I will if its the only thing left for me to do. If you need anymore details I will try to provide them. Also, I am not entirely sure what Android version it had, but I beleive it was up to date. Thanks.
Solution: We’ve previously published a post on how to fix S8 stuck-in-bootloop issue. If you’ve already tried all the troubleshooting steps in that article, then the problem is most probably beyond your ability to fix at this time.
Bootloop is usually a phenomenon that occurs if Android OS is unable to complete the entire boot sequence. In most cases, bootloop can occur after a failed flashing procedure or when using a rooting software. In other situations, it can occur out of the blue due to other unknown factors. Sometimes, a bad battery can manifest in bootloop if Android is unable to finish booting up before power cuts out again. If a bad battery can provide enough power to allow the system to load, random restart issue can be the result instead. Telling you that you have a battery issue is speculation on our part but given the circumstances you mention and the fact that the device was working normally before the issue occured, this is the most likely cause.
The only way to know where the problem lies, of course, is by doing a physical check on the device. If we are correct to say that this is a battery issue, replacing the battery should be a relatively easy fix. We are not eliminating the fact that other factors might be at play here though so the best thing that you can do right now is to have the phone checked by a professional. We suggest that you let a Samsung technician handle the repair.