Laser printer faults and maintenance skills

I. No image repair in the front half of the printer printing page

An HP kserjei laser printer usually displays the first half without an image on the printed page. The latter half is the first half of the original, but the image is normal and not deformed.

Faults indicate that the paper is not properly supplied. Under normal circumstances, when the paper is rubbed to the upper and lower counterpoint rollers, the counterpoint rollers are not in the rotating state, but in a short stop state, after the Controller receives the position signal output by the position sensor on the scanner track, the position roller rotates, and the paper is sent to the rotating drum. The speed of the output paper is equal to the line speed of the rotating drum, the front end of the paper is aligned with the front end of the photosensitive drum image. After being transferred and fixed, a printing page with the same as the original is obtained.

If the speed of the printed paper is equal to the linear speed of the photosensitive drum, the first half of the printed page is blank, no image, and the second half is the first half of the original, and the image is normal, otherwise the image is deformed.

As can be seen from the above, the reason is that there is a problem with the sensor or controller, checking the sensor on the frame next to the scanner track. A sensor is found to be faulty, resulting in forward delivery of paper to the counterpoint roller. After replacing the sensor, the sensor is printed and the fault is rectified.

The scanner advances to the supply side and cannot return to the original position a huipu laser printer. During the continuous printing process, the scanner suddenly advances to the supply side of the printer and cannot return to the original position, the printer made an abnormal noise. The reason why the scanner cannot return the original position is as follows:

(1) poor performance of the returned sensor.
(2) Poor controller performance.
(3) poor contact with the sensor controller is returned.
(4) mechanical faults in the scanner drive system.

According to the fault phenomenon, it occurs suddenly in the continuous printing, accompanied by abnormal sound, so it is suspected that the mechanical part of the scanner drive system is faulty.

Turn on the printer, move the scanner back and forth with your hands, and feel very difficult to move. Under normal circumstances, it is very lightweight to move the scanner with your hands. For this reason, the scanner is pushed back to the original position, boot observation, and the panel display is normal, when the main motor starts to rotate, the scanner also begins to move forward. The exposure light is not bright, and no abnormal "" sound is heard during the scanner's movement. This "" sound is mostly triggered when the scanner enters the end of the track and the rack is touched. Under normal circumstances, when the printer is preheated to a certain temperature, the spindle motor starts to rotate. If the scanner is in the original position, it will remain static. If the scanner is not in the original position, it should immediately return the original position.

Turn on the printer and move the scanner back and forth with your hands for further checks. All the chains are rotated. Normally, when the scanner is mounted, only the drum wheel around the scanner driving the wire rope rotates, the chain does not rotate, so it seems that there is a problem between the drum wheel and the drive sprocket. They are all the driving components of the scanner. The sprocket is located on the inside of the drum wheel. under the action of the clutch, the drive shaft rotates and the drum wheel rotates. After inspection of this part of the removal, it is found that the ball bearing in the wheel has been seriously worn out, the drive shaft is honed out of a slot, the sprocket and the drive shaft are killed, so that when the sprocket starts to rotate, the drive shaft is driven to rotate along with the drum wheel at the same time. This leads to a fault that the scanner can only forward but cannot return.

To completely eliminate faults, replace the New clutch and install other components on the test machine in the original position to restore the operation to normal and rectify the faults.

2. The printer does not respond when a printing job is sent from the software.

There is a whirlpool laser printer. When the printer sends a print job from the software, if the printer does not respond, the cause and troubleshooting methods are as follows:

(1) The power cord is not connected to the printer or cannot be connected to the printer. Check the power supply and power connection lines to make the connection firm.
(2) The printer may be suspended and in sleep state, use software to recover or wake up the printer.
(3) The connection cable between the printer and the computer is not properly connected and the connection cable between the printer and the computer is firmly connected.
(4) Defective connection cable: the cable can be tested on a normal machine to verify whether there are any faults. If it is verified to be defective, a new cable should be replaced.
(5) The incorrect printer check software printer selection menu is selected in the software to check whether the correct printer is selected.
(6) If no printer port is configured correctly, check the configuration menu of the software to ensure that the correct printer port is accessed. If the computer used is not a parallel port, ensure that the printer cable is connected to the correct port.
(7) The printer is connected to an incorrect converter. Check the converter settings and directly connect the printer to the computer to verify whether the converter is correct.
(8) The printer should be repaired in case of a Printer fault.

3. The entire printed page is pale

A laser printer, the entire printed page is pale. The causes of this fault are:

(1) There is not enough toner in the toner cartridge. Check the volume of toner in the toner cartridge. If it is close to use, replace the toner cartridge or add toner.
(2) Toner is adequate, but the concentration is too light. Adjust the toner concentration again to make it light and thick.
(3) the photosensitive intensity of the photosensitive drum is not enough. Adjust the photosensitive Intensity again to make the photosensitive strength sufficient.
(4) the working status of the drum heater is poor. Check the working status of the drum heater to ensure that it works well.
(5) leakage of High Voltage electrode wires and low charging voltage. check whether there is leakage of High Voltage electrode wires connected to the Fixing Frame. If yes, insulation treatment should be performed.
(6) There is a change in the position of the printing board. Check whether the position of the printing board has changed. If the position has changed, adjust the position to ensure that the transfer voltage is sufficient.

4. Paper jam on the output part

A canon laser printer, whether printing large or small sheets of paper, is stuck in the output part. The upper case is normal, only one piece of paper is rubbed, while the lower case is rubbed multiple pieces of paper.

When you turn on the machine check, you can see that a single piece of paper passes through the two paper roller of the paper feed component, but the paper does not move forward, and there are multiple pieces of paper stuck in the front of the paper roller of the paper feed component, and stops there. It indicates that there is a gap between the paper clip roller and the paper feed roller. The friction between the paper clip roller and the paper feed roller cannot be obtained, leading to the suspension of the paper, due to the long-running paper jam, the spring deformation on the clip-paper roller shelf of the paper feed component loses elasticity. As a result, the clamping force of the clip-paper roller is insufficient, and there cannot be friction between the paper and the paper feed roller, although the paper can pass through the paper roll smoothly, it cannot move forward.

Touch the clip-paper roller frame with your hands. The frame has been deformed. Remove the clip-paper roller frame. Replace the new spring and re-Load it. The test machine is printed. The work is back to normal and the fault is rectified.