no video after lcd/inverter replacement

Carefully check the original inverter cable to see if the cable skin is damaged. If so there' a possibility of a short in the hinge and a damage to the logic board inverter circuitry. It happens if the unit is dropped or if the inverter cable is pinched in the hinge. The MacBook screen lightning system is simple. Power goes from the logic board inverter socket to the inverter board via the inverter cable. The LCD display backlight gets its power from the inverter board so if the inverter cable, the inverter board, the LCD backlight are functional then the logic board can be the culprit. You have to test if there's voltage going out of the logic board inverter socket.