Why Is The Table Of The Woodworking Engraving Machine Not Adsorbed?

When using the woodworking engraving machine, there may be no suction on the adsorption table and no adsorption on the board. What is the reason?
1. Clean the filter blockage in the vacuum pump;
2. Reverse the motor, and change the direction of the motor by any two wires;
3. Repair the table or pipeline if there is air leakage;
4. Is the motor line voltage normal;
5. Is there less water in the water circulation air pump, is the motor stuck or rusted, and remove the motor fan protection net and rotate the axis.