Laser and computer connection is not on what reason be?

Laser and computer even don't have the following several reasons: laser and computer even no reasons 1, connect the cable to see if there is problem; Laser and computer even no reasons 2, computer laser machine drive is installed correctly; Laser and computer even no reasons 3, laser machine is a state of normal work; Laser and computer don't reason 4, laser and computer connection communication port is set correctly. Laser and computer even not of the above several reasons generally have ruled out one by one, believe that you can find the laser and computer even no reasons.