First, check for voltage at the lock if voltage is present and the door is not locked then the lock is the problem.
Second, if you do not have voltage at the lock check the sensitivity adjustment potentiometer on the back of the board turning the POT counter-clockwise will decrease the sensitivity and the bar may begin to function.
Third, if adjusting the sensitivity does not work try removing the red wire of the harness from positive DC if the door does not lock check for voltage between the white and black wire of the harness if you have no voltage then an upstream switch is more likely the problem.
Fourth, check the surrounding area for anything that might generate an RF field such as neon signs or loss prevention gates disconnect the device and see if the bar begins working properly, if it does then the addition of a 22,000 micro Henry inductor in-line between the board and the bar should solve the problem. If this does not work and everything else checks out contact the factory.