My Samsung Galaxy S5 phone screen goes black when on phone, preventing me from using Options.

[AC Question]

To stop screen going black while on a call. Set Calls on Home button to Answer. Use Keypad to dial. Press Speakerphone. When screen darkens. Press anywhere on Keypad to restore. If Screen is Black, restore by pressing on Home Button. That restores the light again
Daina Tebecis