Have a Galaxy S8 or Galaxy S8 Plus? You may have encountered the device having blank screen right after turning it on. The buttons light up and seem to work normally, but the screen stays black and looks as if it is not functioning at all.
This bug can happen at different times for different users. The general problem is the screen failing to activate when the phone is started. Here we provide several possible solutions that you can try to get your screen back on should this unusual occurrence happen with your Samsung Galaxy S8 or Galaxy S8 Plus.
A factory reset will ensure any recent changes you have made to the phone that may be causing the issue are corrected. Try following this step by step explanation of how to factory reset your Galaxy S8 and Galaxy S8 Plus . The process will delete all the data and files you have on your phone. Be sure to backup important files before going through with it.
Boot Recovery Mode to Wipe the Cache Partition
Follow these steps to start the device in recovery mode and Wipe the Cache Partition:
- Get the phone into Recovery Mode.
- The phone will vibrate. Release the Power button when it first vibrates but keep holding the Volume up and Home buttons until the sign for “Android System Recovery” appears on screen.
- Tap the “Volume Down” button to scroll and find “wipe cache partition”, press the Power button over it to start it.
- Once the cache partition is deleted, the Galaxy S8 will restart.
You can take a look at the guide outlined here for more expansive details on how to clear the cache on your the Galaxy S8 or Galaxy S8 Plus. 
If the above methods did not resolve your issue, you can try taking your device to a trained Samsung Galaxy S8 and Galaxy S8 Plus expert repair technician. If the device proves defective, they may be able to offer a repair service or replacement phone.