To clear the cache partition you need to connect your phone to A PC then Turn off the device. This is important as your device won’t boot to Recovery Mode when it’s on.
Press and hold the Volume Up key and the Bixby/Power key.
Once the Android Recovery screen comes up, release the buttons.
Use the Volume Down button until you are highlighting ‘Wipe cache partition.’
Press the Power button to select ‘Wipe cache partition.’
Use Volume Down to highlight Yes.
Press the Power button to confirm the action to clear the cache.
Wait for a second as the system wipes the cache.
Press the Power button again to reboot the device. Hope this helps.
