The AB Dicks with the digital display had some safety switches that were sensitive to press vibration and the press would stop and you had to clear and start again. There is a service bypass switch that allows the tech to override the safety switches and if all was fine after that, the problem was in the safety system. With the covers off and the machine running, I used to tap the safety switches with the handle of a screwdriver to see if those vibrations would stop the machine. I had the most trouble with the clear plastic ones with a plastic button actuator in the top-center and actuated with a cam. They were used for the ink-water guard, master and blanket guard and the chain guard. The switches are adjustable and it may be that the cam actuator is tuching gthe button actuator of the switch and press vibration causes the problem. It happens so quick that you cANN