1. Firstly, check and clean the nozzle plate, gently wipe the surface of the nozzle with a dust-free cloth and specialized cleaning agent to ensure that there is no dry ink or impurities blocking the nozzle hole, as even small blockages can cause the direction of ink line spraying to deviate, affecting the printing quality.

2. Secondly, carefully inspect and clean the charging slot to ensure that there are no residual ink crystals or pollutants in its internal electrodes and gaps. If necessary, use an ultrasonic cleaner for deep cleaning to ensure that ink droplets can obtain uniform and accurate charging when passing through the charging slot.

3. Next, adjust the position of the ink line by using the adjustment knob or software parameters on the device to finely move the nozzle head or Venturi position, so that the ink line can pass through the center of the recovery hole, ensuring smooth ink recovery and avoiding deviation or splashing caused by poor recovery.

4. Then, check and adjust the pressure system, including ink pressure, viscosity, and other parameters, to ensure that it strictly meets the standard range specified by the equipment manufacturer, as unstable pressure or viscosity deviating from the standard can directly change the fluid characteristics of the ink, resulting in unstable ink line trajectories.

5. Observe and correct ink line breakpoints, adjust the breakpoint value through the built-in phase detection tool or visual observation of the device to make it in the optimal position. Discontinuities that are too long or too short can cause inaccurate ink droplet flight trajectories, leading to ink line deviation and character deformation.

6. Perform precise calibration of the nozzle level, using tools such as a spirit level to ensure that the nozzle is installed completely horizontally and parallel to the plane of the product conveyor belt. Any small inclination angle will be amplified in the spraying distance, causing the ink line to fall off the mark. This is the fundamental and critical mechanical calibration.

7. Check if the grounding wire is well connected to ensure that the equipment, nozzle, and surrounding conductors (such as conveyor belts) are reliably and independently grounded. Poor grounding can introduce electrostatic interference, affecting the charging and flight path of ink droplets, which is a common cause of random ink line deviation.

8. Verify and calibrate the high-voltage power supply package, use a multimeter to check whether the high-voltage values of key parts such as the charging electrode and deflection plate are stable and meet the settings. Unstable high voltage can directly cause uneven charging of ink droplets and distortion of the deflection electric field, and the faulty module must be repaired or replaced in a timely manner.

9. Perform a comprehensive inspection of the ink system's sealing, with a focus on checking for leaks or air intake points in components such as filters, pipeline joints, and pumps, as air entering the sealed ink system can form bubbles that interfere with the stability of ink flow and are potential causes of sudden ink line deviation.

10. Finally, if the above steps are ineffective, it is necessary to consider replacing key components, such as attempting to replace different batches of ink to rule out ink compatibility issues, or replacing core components such as nozzles, charging slots, and Venturi to determine if there are faults caused by component aging or hidden damage.