one. Repair without images in the front half of the printer print page
An HP kserJei laser printer often has no image on the printed page, and the second half prints the first half of the original, but the image is normal and has no deformation.
Fault phenomenon: It indicates that it is caused by poor paper supply of the alignment. Under normal circumstances, when the paper is rubbed between the upper and lower alignment rollers, the alignment roller is not in a rotating state, but in a brief stop state. When the controller receives the alignment signal output from the alignment sensor located on the scanner track, the alignment roller rotates, and the paper is sent to the rotating photosensitive drum, and the speed of the paper is sent out is equal to the linear speed of the rotation of the photosensitive drum. The front end of the paper is aligned with the front end of the image on the photosensitive drum, and then transferred and fixed, a printed page is obtained that is the same as the original.
When the printing paper is sent out in advance by the alignment roller, if the speed of the paper being sent out is equal to the linear speed of the photosensitive drum, the printing page will be blank with no image, and the second half will be the first half of the original, and the image will be normal, otherwise the image will be deformed.
As can be seen from the above, the reason is that there is a problem with the alignment sensor or controller, check the sensor on the rack next to the scanner track. I found that there was a problem with a sensor, causing the alignment roller to feed paper in advance, and then try to print the sensor, and troubleshooting.
When the scanner goes to the paper feed side, it cannot return to its original position. During continuous printing, the scanner suddenly goes to the paper feed side of the printer and cannot return to its original position, and the printer makes an abnormal "whatever" sound. The reasons why the scanner cannot return to its original position are as follows:
(1) Return to poor sensor performance.
(2) The controller performance is poor.
(3) Return to the sensor controller with poor contact.
(4) There is a mechanical failure in the scanner drive system.
According to the fault phenomenon, it occurs suddenly during continuous printing and is accompanied by abnormal sound, so it is suspected that the mechanical part of the scanner driving system is faulty.
Turn on the printer and move the scanner back and forth with your hands. It feels very difficult to move. Under normal circumstances, it is very light to move the scanner by hand. For this reason, push the scanner back to its original position and turn it on and observe. The panel displays normally. When the main motor starts to rotate, the scanner also begins to move forward. The exposure light is not on, and no abnormal "nothing" sound is heard during the scanner movement. This "nothing" sound is mostly caused by the scanner entering the end of the track and colliding with the rack. Under normal circumstances, when the printer is preheated to a certain temperature, the spindle motor begins to rotate. If the scanner is in the original position, it will remain stationary; if the scanner is not in the original position, it should immediately return to the original position.
When you turn on the printer and check further, you move the scanner back and forth with your hands. You find that all chains rotate accordingly. Under normal circumstances, when you move the scanner frame, you only rotate around the drum with the scanner driving wire rope, and the chain does not rotate. From this, it seems that there is a problem with the drum and the driving sprocket. They are both scanner driving components. The sprocket is located inside the drum. Under the action of the clutch, the driving shaft rotates and drives the drum to rotate. After disassembly inspection of this part, it was found that the ball bearing installed in the center of the wheel was seriously worn, and the drive shaft was worn out with a groove, which bit the sprocket and the drive shaft to death. In this way, when the sprocket starts to rotate, the drive shaft is driven, rotating with the drum at the same time, driving the drum shaft to rotate in one direction, resulting in a fault that the scanner can only move forward but cannot return.
In order to completely eliminate the fault, after replacing the new clutch, install the other parts in place and the test machine will be tested, and the work will return to normal and troubleshoot.
An HP kserJei laser printer often has no image on the printed page, and the second half prints the first half of the original, but the image is normal and has no deformation.
Fault phenomenon: It indicates that it is caused by poor paper supply of the alignment. Under normal circumstances, when the paper is rubbed between the upper and lower alignment rollers, the alignment roller is not in a rotating state, but in a brief stop state. When the controller receives the alignment signal output from the alignment sensor located on the scanner track, the alignment roller rotates, and the paper is sent to the rotating photosensitive drum, and the speed of the paper is sent out is equal to the linear speed of the rotation of the photosensitive drum. The front end of the paper is aligned with the front end of the image on the photosensitive drum, and then transferred and fixed, a printed page is obtained that is the same as the original.
When the printing paper is sent out in advance by the alignment roller, if the speed of the paper being sent out is equal to the linear speed of the photosensitive drum, the printing page will be blank with no image, and the second half will be the first half of the original, and the image will be normal, otherwise the image will be deformed.
As can be seen from the above, the reason is that there is a problem with the alignment sensor or controller, check the sensor on the rack next to the scanner track. I found that there was a problem with a sensor, causing the alignment roller to feed paper in advance, and then try to print the sensor, and troubleshooting.
When the scanner goes to the paper feed side, it cannot return to its original position. During continuous printing, the scanner suddenly goes to the paper feed side of the printer and cannot return to its original position, and the printer makes an abnormal "whatever" sound. The reasons why the scanner cannot return to its original position are as follows:
(1) Return to poor sensor performance.
(2) The controller performance is poor.
(3) Return to the sensor controller with poor contact.
(4) There is a mechanical failure in the scanner drive system.
According to the fault phenomenon, it occurs suddenly during continuous printing and is accompanied by abnormal sound, so it is suspected that the mechanical part of the scanner driving system is faulty.
Turn on the printer and move the scanner back and forth with your hands. It feels very difficult to move. Under normal circumstances, it is very light to move the scanner by hand. For this reason, push the scanner back to its original position and turn it on and observe. The panel displays normally. When the main motor starts to rotate, the scanner also begins to move forward. The exposure light is not on, and no abnormal "nothing" sound is heard during the scanner movement. This "nothing" sound is mostly caused by the scanner entering the end of the track and colliding with the rack. Under normal circumstances, when the printer is preheated to a certain temperature, the spindle motor begins to rotate. If the scanner is in the original position, it will remain stationary; if the scanner is not in the original position, it should immediately return to the original position.
When you turn on the printer and check further, you move the scanner back and forth with your hands. You find that all chains rotate accordingly. Under normal circumstances, when you move the scanner frame, you only rotate around the drum with the scanner driving wire rope, and the chain does not rotate. From this, it seems that there is a problem with the drum and the driving sprocket. They are both scanner driving components. The sprocket is located inside the drum. Under the action of the clutch, the driving shaft rotates and drives the drum to rotate. After disassembly inspection of this part, it was found that the ball bearing installed in the center of the wheel was seriously worn, and the drive shaft was worn out with a groove, which bit the sprocket and the drive shaft to death. In this way, when the sprocket starts to rotate, the drive shaft is driven, rotating with the drum at the same time, driving the drum shaft to rotate in one direction, resulting in a fault that the scanner can only move forward but cannot return.
In order to completely eliminate the fault, after replacing the new clutch, install the other parts in place and the test machine will be tested, and the work will return to normal and troubleshoot.