Laser printer Failure overhaul Daquan 1th/2 page _ Hardware Maintenance

A Maintenance of no image in the front half of the printer's printed page

An HP Kserjei laser printer, on the printed page often appear in the first half of the image, the second half of the manuscript is printed in the first half of the original, but the image is normal, no deformation.

Failure phenomenon: Indicates that the paper is caused by poor, under normal circumstances, when the paper is rubbed to the top and bottom of the bit roll, the bit roll is not in the rotation state, but in a transient stop state, when the controller receives the position sensor output in the scanner orbit to the bit signal, the bit roll rotation, the paper is sent to the spinning of the photoconductor drum, And the speed of the paper and the photographic drum rotation of the line speed is equal, the front of the paper and the photographic drum on the front end of the image, and then transfer, fixing, that is, a copy of the same printed page with the original.

When the paper is sent in advance to the bit roll, if the speed of being sent out is equal to the line speed of the photoconductor drum, then the printed page is the first half blank, no image, the second half is the first half of the manuscript, and the image is normal, otherwise the image is distorted.

The reason for this is that there is a problem with the bit sensor or the controller, which checks the sensor on the frame next to the scanner track. Found a sensor problem, resulting in a bit of the roll in advance feed, replace the sensor after the trial printing, troubleshooting.

The scanner advances to the feed side can not return in situ an HP laser printer, in the continuous printing process, the scanner suddenly advance to the printer's paper side and can not return to the original, the printer issued "How do" the abnormal sound. The reason the scanner cannot return in situ is as follows:

(1) The return sensor has poor performance.
(2) Poor performance of the controller.
(3) Return to the sensor controller bad contact.
(4) The scanner drive system has mechanical faults.

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

Open the printer, with the hand back and forth to move the scanner, feel the movement is very difficult, under normal circumstances with the hand mobile scanner is very light, for this, the scanner back to the original, power on observation, panel display Normal, when the main motor began to rotate, the scanner also began to move forward. Exposure light is not bright, the scanner is moving in the process did not hear the abnormal "how do" sound, this "how Do" sound is more than the scanner into the end of the track with the rack collision issued. Under normal circumstances, when the printer preheating to a certain temperature, the spindle motor began to rotate, if the scanner in situ, then static; If the scanner is not in place, you should immediately return to the original position.

Open the printer and move the scanner back and forth with your hand found that all the chain is followed by rotation, and under normal circumstances, mobile scanner racks, only around the scanner-driven wire rope drum rotation, the chain is not rotating, which appears to be the drum and drive sprocket problems, they are the scanner drive parts, The sprocket is positioned on the inside of the drum wheel, and the driving shaft rotates to drive the drum wheel rotation under the action of the clutch. After this part of the demolition inspection, found that the wheel heart ball bearing wear serious, the drive shaft is milled out of a groove to kill the sprocket and drive shaft, so that when the sprocket starts to rotate, the drive shaft is driven, and the drum wheel rotates at the same time, driving the drum axle in one direction, causing the scanner to advance but not return the fault.

In order to completely eliminate the fault, replace the new clutch, the other parts in situ installed test machine, work back to normal, troubleshooting.

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