Note nine screen flickering green on screen dieing

[galaxyalphahype]

[BandOfBrothers]

Hi @galaxyalphahype 

Try a forced reboot by holding down the volume down key and power button simultaneously for more than 7 seconds to restart it. When your phone resets, you will feel it vibrate.

If that does not help then try >

• Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop or use a Tv's USB Port to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too { Possibly excluding the s²⁴ Series of phone's } 
• Safe Mode  > https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ turns off downloaded apps and themes etc which may highlight an app or theme that's causing conflict. Alternatively long press the power off button and then long hold on Turn Off to get to Safe Mode. 

If all else fails a Samsung Service Centre can assess your phone > https://www.samsung.com/uk/support/repair/ 

If i can be of any further help please don't hesitate to ask  😎