Issues with HC-12 module

Yeah I'm not sure! I'm frustrated because I feel there is no absolute way to check if they are actually functional or not... As I said, I can't seem to even communicate through the SET pin which is indicative that the module is fried... There were other components in the circuit to begin with (potentiometers/LEDs) but I have since tried the boards on their own with no peripherals so I am logically at a loss.