How to solve the problem of air pump in cup printing machine?

How to solve the problem of air pump in cup printing machine? The air pump in the cup printer cannot be started normally. There are several inspection methods:

1. check whether the air pump start button and air pump stop button (normally closed point) are normal. 2. check whether the paper counter of the cup printer reaches the preset number. If the set number of paper is reached, the number displayed on the counter flashes. Press the reset key to reset the counter before starting the air pump. 3. check whether the AC fuse in the control box is fused (its position is on the left side of the AC contactor). 4. press the air pump start button to check whether the D8 indicator light on the circuit board is on. If the indicator light is on, please use the AC Gear of the multimeter to measure the terminals 54 and 51 of the circuit board to see whether the display of the meter is 220V. If there is 220V, check the AC contactor; If there is no 220V; Check whether the screw fuse of the circuit board is blown.