NBA Hoops uses a inferred sensor to detect the ball entering the hoop. The sensor is connected to the J1 connector on the back side of the time display board. The newest revision of net sensor is blue and has two indicator LEDs on the back side, the green LED indicates power and the orange LED indicates alignment. The older revision of the net sensor was black and had 1 red led in the front to indicate power and 1 orange LED on the back. On both version of the net sensor the orange LED will be solid on when the sensor is perfectly aligned and flashing when on the edge of alignment. You can check the power and the signal for the net sensor using a multi meter at the J1 connector on the time display.
Pin 1 - brown wire - 12vdc
Pin 2 -black wire - score signal
Pin 3 - blue wire - ground
To check the score signal place your meter on pin 2 and pin 3 of J1 set to DC voltage. When the sensor is aligned you will get 5vdc and when the sensor is blocked you will see 0vdc.
If the change of state is being seen at the J1 connector on the time display board and the score is not advancing then replace the time display boards.