Under normal circumstances, the left and right displacement of the chariot in the needle printer chariot mechanism should be smooth and stable. In this way, after the printer is turned on, no matter where the chariot is in its original position, it can return to the original position at the left end. When the printer is working, the chariot carries the printhead and moves back and forth. If the font car fails, the printhead will not move in place or not move at all, resulting in the printing work being unable to be completed. Let’s discuss with you the following specific aspects. The failure of the word car is mainly reflected in the following aspects.
1. Too much dirt in the zipper mechanism often causes the zipper to fail to return to the position smoothly. At this time, cleaning methods can be used to troubleshoot the fault.
2. The mechanical failure of the font car mechanism, such as the wear of the font car belt, the parallelism of the front and rear guide rails, etc., will also prevent the font car from returning to position and moving smoothly. In this case, you can only replace the font-car belt or font-car guide rail.
3. Car motor failure
The fault of the byte motor itself is mainly caused by the burnout of one or more phase winding coils of the stepper motor (short-circuit, open-circuit). This fault can be directly measured by a multimeter to measure the DC resistance value of the motor coil winding and then compared with the normal resistance value (generally, the four sets of coils of the motor will not burn out all, and there are always one or more groups that are good) to make a judgment. If one or both phases of the motor coil are burned out, as long as the coil frame does not deform (the rotation shaft rotated by hand is not obviously stuck), you can burn it by yourself according to the original wire diameter and number of turns of the motor (when removing the burned coil, pay attention to count the turns and then use a centimeter to measure the wire diameter). If the coil frame of the motor has been severely deformed, a new motor should be replaced. In addition, during the long-term use of the printer, due to vibration and other reasons, the magnetic steel in the motor may demagnetize, resulting in insufficient rotation torque of the motor, which makes it difficult for the printer to move the car during the printing process. In this case, you should replace the new motor of the same model.
4. Switch circuit failure
For printers that use the "high voltage drive low voltage lock" motor drive system, such as AR-3240, AR-2463, AR-3200, LQ-1500, LQ-800/1000 printers, there are often breakdown or open circuits between the transistors c-e that supply high voltage in the high/low voltage switching circuit. If the c~e poles break down, the driving high voltage will be applied to the winding of the stepper motor, which may further cause the motor winding to burn out and burn out the transistor used as the phase signal of the stepper motor. If the circuit is open between the c~e poles, the high voltage cannot supply the motor of the car, and the motor does not run, the car will not move.
In addition, it is possible to fail in the control signal part of the high/low voltage switching. At this time, it should be detected and eliminated according to the circuit of the specific printer model.
5. Phase failure of vehicle motor
After the printer is powered on, if there are one or two sets of open circuits on the four-phase windings of the stepper motor, the word car will shake in its original position or the word car is weak, or even the word car does not move. This phenomenon may be due to poor contact or disconnection of the plug of the zipper motor, or the phase control part of the zipper motor control and driving circuit. Since the circuits of various printers are different, specific circuits should be analyzed and tested, fault points should be found, and eliminated.
6. The stepper motor driver or its peripheral components are damaged
Stepper motor drivers are some printers used to control transistors or application-specific integrated circuits that drive motors. For example, the chariot stepper motors in the AR-3240 printer and the M-2724 printer use transistors D1579 and D1789 as their respective chariot motor drivers, while the SLA7026M is used as the chariot motor drivers in the DLQ-2000K, AR-4400 and CR-3240 printers. If these devices are damaged, the chariot will not work normally. Only by replacing damaged components can you troubleshoot the fault.
7. The special gate array circuit failure of the font car motor drive circuit
The CPU controls the motor drive circuit of the car by a dedicated gate array circuit (such as E05A09BA in the LQ-1600K printer) or I/O interface circuit (such as E05A24GA in the DLQ-2000K printer and XBL-2 in the AR-3200 printer). If this part of the circuit is damaged, it will affect the normal operation of the car, and even the car will not return to its original position when the printer is powered on.
Although the fault of the word car can be attributed to the above five parts, from the perspective of maintenance, specific analysis and diagnosis should be carried out based on the various fault phenomena that occur in the printer. The inspection sequence is generally: printer font mechanism (mechanical fault)--font motor (resistance value and torque of each phase)--font motor The resistance value of the drive output socket (positive and inverting phase resistance)--font motor drive power supply voltage---ground resistance at the input and output end of the drive circuit ---font motor phase control circuit.
The following are three examples of vehicle failure analysis and troubleshooting:
1. The CR-3240 printer is running abnormally after it is turned on.
Fault phenomenon: After the CR-3240 printer is turned on, the font car can return to its initial position, and the printer "crashed" when the font car moves to the right during printing.
Diagnosis and exclusion: The font car can return to the initial position, which means that the printer's control logic is normal and the control signal of the font car motor is also normal, mainly because the font car motor's torque is insufficient. In addition to the lack of phase operation of the motor, there are two other reasons: one is that the voltage of the driving power supply is low, and the other is that the motor itself is demagnetized due to vibration due to long-term use of the motor. If the possibility of faults in the car motor drive circuit SLA7026M and its peripheral circuits are eliminated, troubleshooting will be resolved by replacing a new car motor using the replacement method.
2. The AR-3200 printer is running abnormally after it is turned on.
Fault phenomenon: After the AR-3200 printer is turned on, the cart shakes in its original position. Push the cart with your hand and moves it for a distance before stopping to alarm.
Diagnosis and troubleshooting: From the analysis of fault phenomena, it is because of the failure of the printer's font car, which is generally the failure of the control and driving circuit of the font car mechanism and the font car motor. Check the car mechanism first in the order of inspection and troubleshoot this part of the troubleshooting. Then measure the resistance of each phase of the coil of the car motor, each phase is 5Ω, which is a normal value. Then, the torque of the AR-3200 printer is checked by the replacement method (the torque of the AR-3200 printer will drop after being used for a period of time), and the torque does not change, thus eliminating the possibility of AR-3200 motor failure. The ground-disconnection resistance of each pin of the motor drive output plug CN5 on the main control circuit board was measured, and the second pin was short-circuited to the ground. Follow this end and check that the phase signal output end (pin 9) of the motor drive circuit SLA4030 (TA7) of the car is short-circuited to the ground. This determines that the SLA4030 is damaged. After the SAL4030 is replaced, the troubleshooting will be solved.
3. After the LQ-1900K printer is turned on, the cart shakes, and the cart can move with your hand.
Diagnosis and analysis: From the perspective of phenomenon, there are two reasons: one is the mechanical failure of the printer, and the other is the fault of the font car motor and its control and driving circuit, and it is because a phase of the font car motor is not working properly. For the mechanical failure of the printer, under normal circumstances, the left and right displacement of the font car should be smooth and stable. In this way, after the printer is powered on, no matter where the font car was originally parked, it can return to the initial position. If there is too much dirt in the font car mechanism, or the axle bushing of the font car frame is worn seriously, causing the font car frame to shake on its shaft, it will cause the font car to return to the initial position smoothly due to excessive resistance during movement, or it will not be in place when returning to the initial position. The solution is to remove the trolley mechanism and clean it. The shaft sleeve should be replaced for the frame with severe wear of the shaft sleeve. After the above inspection, the font car motor drive circuit was initially diagnosed. Static measurement of the DC resistance of each phase coil of the car motor. The measured resistance value is about 5Ω, which means that the motor of the car is normal. Use an oscilloscope to observe the output waveforms of each input terminal (pins 1, 8, 11, 18) of the motor driving circuit of the car SLA7024M, and find that there is no waveform output for pin 8. Static measurement of the forward and reverse resistances of pin 8 to ground, and the measured forward and reverse resistance values are 1KΩ, while the normal forward resistance value should be ∞, and the reverse resistance value should be 7.5kΩ, which means that the 8 pin of SLA7024M has been damaged. After replacement, troubleshooting.
1. Too much dirt in the zipper mechanism often causes the zipper to fail to return to the position smoothly. At this time, cleaning methods can be used to troubleshoot the fault.
2. The mechanical failure of the font car mechanism, such as the wear of the font car belt, the parallelism of the front and rear guide rails, etc., will also prevent the font car from returning to position and moving smoothly. In this case, you can only replace the font-car belt or font-car guide rail.
3. Car motor failure
The fault of the byte motor itself is mainly caused by the burnout of one or more phase winding coils of the stepper motor (short-circuit, open-circuit). This fault can be directly measured by a multimeter to measure the DC resistance value of the motor coil winding and then compared with the normal resistance value (generally, the four sets of coils of the motor will not burn out all, and there are always one or more groups that are good) to make a judgment. If one or both phases of the motor coil are burned out, as long as the coil frame does not deform (the rotation shaft rotated by hand is not obviously stuck), you can burn it by yourself according to the original wire diameter and number of turns of the motor (when removing the burned coil, pay attention to count the turns and then use a centimeter to measure the wire diameter). If the coil frame of the motor has been severely deformed, a new motor should be replaced. In addition, during the long-term use of the printer, due to vibration and other reasons, the magnetic steel in the motor may demagnetize, resulting in insufficient rotation torque of the motor, which makes it difficult for the printer to move the car during the printing process. In this case, you should replace the new motor of the same model.
4. Switch circuit failure
For printers that use the "high voltage drive low voltage lock" motor drive system, such as AR-3240, AR-2463, AR-3200, LQ-1500, LQ-800/1000 printers, there are often breakdown or open circuits between the transistors c-e that supply high voltage in the high/low voltage switching circuit. If the c~e poles break down, the driving high voltage will be applied to the winding of the stepper motor, which may further cause the motor winding to burn out and burn out the transistor used as the phase signal of the stepper motor. If the circuit is open between the c~e poles, the high voltage cannot supply the motor of the car, and the motor does not run, the car will not move.
In addition, it is possible to fail in the control signal part of the high/low voltage switching. At this time, it should be detected and eliminated according to the circuit of the specific printer model.
5. Phase failure of vehicle motor
After the printer is powered on, if there are one or two sets of open circuits on the four-phase windings of the stepper motor, the word car will shake in its original position or the word car is weak, or even the word car does not move. This phenomenon may be due to poor contact or disconnection of the plug of the zipper motor, or the phase control part of the zipper motor control and driving circuit. Since the circuits of various printers are different, specific circuits should be analyzed and tested, fault points should be found, and eliminated.
6. The stepper motor driver or its peripheral components are damaged
Stepper motor drivers are some printers used to control transistors or application-specific integrated circuits that drive motors. For example, the chariot stepper motors in the AR-3240 printer and the M-2724 printer use transistors D1579 and D1789 as their respective chariot motor drivers, while the SLA7026M is used as the chariot motor drivers in the DLQ-2000K, AR-4400 and CR-3240 printers. If these devices are damaged, the chariot will not work normally. Only by replacing damaged components can you troubleshoot the fault.
7. The special gate array circuit failure of the font car motor drive circuit
The CPU controls the motor drive circuit of the car by a dedicated gate array circuit (such as E05A09BA in the LQ-1600K printer) or I/O interface circuit (such as E05A24GA in the DLQ-2000K printer and XBL-2 in the AR-3200 printer). If this part of the circuit is damaged, it will affect the normal operation of the car, and even the car will not return to its original position when the printer is powered on.
Although the fault of the word car can be attributed to the above five parts, from the perspective of maintenance, specific analysis and diagnosis should be carried out based on the various fault phenomena that occur in the printer. The inspection sequence is generally: printer font mechanism (mechanical fault)--font motor (resistance value and torque of each phase)--font motor The resistance value of the drive output socket (positive and inverting phase resistance)--font motor drive power supply voltage---ground resistance at the input and output end of the drive circuit ---font motor phase control circuit.
The following are three examples of vehicle failure analysis and troubleshooting:
1. The CR-3240 printer is running abnormally after it is turned on.
Fault phenomenon: After the CR-3240 printer is turned on, the font car can return to its initial position, and the printer "crashed" when the font car moves to the right during printing.
Diagnosis and exclusion: The font car can return to the initial position, which means that the printer's control logic is normal and the control signal of the font car motor is also normal, mainly because the font car motor's torque is insufficient. In addition to the lack of phase operation of the motor, there are two other reasons: one is that the voltage of the driving power supply is low, and the other is that the motor itself is demagnetized due to vibration due to long-term use of the motor. If the possibility of faults in the car motor drive circuit SLA7026M and its peripheral circuits are eliminated, troubleshooting will be resolved by replacing a new car motor using the replacement method.
2. The AR-3200 printer is running abnormally after it is turned on.
Fault phenomenon: After the AR-3200 printer is turned on, the cart shakes in its original position. Push the cart with your hand and moves it for a distance before stopping to alarm.
Diagnosis and troubleshooting: From the analysis of fault phenomena, it is because of the failure of the printer's font car, which is generally the failure of the control and driving circuit of the font car mechanism and the font car motor. Check the car mechanism first in the order of inspection and troubleshoot this part of the troubleshooting. Then measure the resistance of each phase of the coil of the car motor, each phase is 5Ω, which is a normal value. Then, the torque of the AR-3200 printer is checked by the replacement method (the torque of the AR-3200 printer will drop after being used for a period of time), and the torque does not change, thus eliminating the possibility of AR-3200 motor failure. The ground-disconnection resistance of each pin of the motor drive output plug CN5 on the main control circuit board was measured, and the second pin was short-circuited to the ground. Follow this end and check that the phase signal output end (pin 9) of the motor drive circuit SLA4030 (TA7) of the car is short-circuited to the ground. This determines that the SLA4030 is damaged. After the SAL4030 is replaced, the troubleshooting will be solved.
3. After the LQ-1900K printer is turned on, the cart shakes, and the cart can move with your hand.
Diagnosis and analysis: From the perspective of phenomenon, there are two reasons: one is the mechanical failure of the printer, and the other is the fault of the font car motor and its control and driving circuit, and it is because a phase of the font car motor is not working properly. For the mechanical failure of the printer, under normal circumstances, the left and right displacement of the font car should be smooth and stable. In this way, after the printer is powered on, no matter where the font car was originally parked, it can return to the initial position. If there is too much dirt in the font car mechanism, or the axle bushing of the font car frame is worn seriously, causing the font car frame to shake on its shaft, it will cause the font car to return to the initial position smoothly due to excessive resistance during movement, or it will not be in place when returning to the initial position. The solution is to remove the trolley mechanism and clean it. The shaft sleeve should be replaced for the frame with severe wear of the shaft sleeve. After the above inspection, the font car motor drive circuit was initially diagnosed. Static measurement of the DC resistance of each phase coil of the car motor. The measured resistance value is about 5Ω, which means that the motor of the car is normal. Use an oscilloscope to observe the output waveforms of each input terminal (pins 1, 8, 11, 18) of the motor driving circuit of the car SLA7024M, and find that there is no waveform output for pin 8. Static measurement of the forward and reverse resistances of pin 8 to ground, and the measured forward and reverse resistance values are 1KΩ, while the normal forward resistance value should be ∞, and the reverse resistance value should be 7.5kΩ, which means that the 8 pin of SLA7024M has been damaged. After replacement, troubleshooting.