When we use a laser printer, it may print out irregular black lines in the horizontal direction. Today we will talk about the causes of this problem and how to deal with it.

Possible causes:
1) Poor contact of the photosensitive drum electrode
2) Excessive shear force of the drum blade
3) The photoconductor drum main gear shakes when it rotates
4) The OPC drum is defective or installed incorrectly

Repair method:

1. Check whether the photosensitive drum de-electrification contact is in good contact.

After the exposure of the photoconductor on the surface of the photosensitive drum, the dot matrix is connected to the conductive base, and the charge is released to the ground through the conductive base of the OPC drum and the de-electrification brush.

For example, the de-electrification brush of the HP 4L and 4P photosensitive drums uses the de-electrification method of friction between the de-electrification brush and the inner wall of the conductive base cylinder. After a certain period of use, the inner wall of the OPC drum is worn out by two deep grooves (double contact), which will cause the contact point to have poor contact with the conductive base of the photosensitive drum. The repair method is to change the original friction track of the contact point, and then apply conductive grease to increase the conductivity.

2. Check whether the blade of the OPC drum is lubricated (whether the shear force is too large).

There is a shear angle between the cleaning blade and the photosensitive drum, and the shear force on the photosensitive drum is very large. In order to ensure good cleaning ability between the OPC drum and the blade, and also to ensure good lubrication without damaging the OPC drum, a layer of lubricating powder is applied to the scraper blade.

After a long time of use, the friction of the lubricating powder disappears or the lubricating powder is wiped off during cleaning, and the blade will form a large shear resistance to the photosensitive drum, causing the drum to run poorly and produce shaking (this usually happens on re-manufactured toner cartridges), which will cause the photosensitive drum to run poorly and cause failure. Therefore, special attention should be paid to not remove the lubricating powder on the blade when cleaning or replacing the OPC drum. To eliminate this fault, the only way is to replace the blade.

3. There are many transmission gears in the printer. After the printer has been used for a certain period of time, there will often be problems such as lack of lubrication and excessive wear between the transmission gears, which will cause the meshing gap between the gears to be too large, causing unstable transmission and shaking. This is also an important reason for the horizontal black line fault.

At this time, you should first adjust the main transmission gear that the photosensitive drum is meshing with, and add some lubricating oil to the gear. If the wear is severe and cannot be adjusted, the main transmission gear that the printer is meshing with the OPC drum should be replaced to eliminate the fault.

4. Another reason for the appearance of horizontal black lines is that the photosensitive drum is defective or installed incorrectly.

When the photosensitive drum is defective, the horizontal black lines or stains that appear on the printed page are mostly regular. At this time, you can remove the toner cartridge and check it carefully. If there is a problem with the photosensitive drum, replace it.

If there is no problem with the photosensitive drum, it may be caused by incorrect installation of the drum. When the photosensitive drum is not installed correctly, it will cause abnormal contact with the printing paper, resulting in uneven printing and black bars. At this time, you should open the printer cover, take out the photosensitive drum, and reinstall it correctly.

Summary:

The above is the reason and solution for the irregular black lines in the horizontal output of laser printers. Welcome to leave a message in the comment area and let’s discuss it together.