The hottest laser printer printing failure and qui

Laser printer printing failure and quick reference manual (1

for laser printers, because their working principles are basically similar, many quality faults can be used by many models. When laser printers are used for a certain number of years, that is, after outputting a certain number of samples, their printing quality will decline, and some parts will have printing quality defects when they are used to the limit. Some of them are because we are not familiar with the working principle and performance of laser printers, because This operation does not adjust it to the best state or is still in the wrong state, and the use of materials does not meet the requirements, which makes the output effect poor. This is what we call the zigzag test, which should be carried out within 55 days after the sample is removed from the medium, as "a fault that is not a fault". It generally does not affect the normal work of the printer, but the printed results are not satisfactory, and so on. Here are some printing quality problems and solutions

1 output a full sheet of black paper

possible fault causes:

(1) if the laser is definitely good, the charging electrode may be short circuited with the grid

(2) scan drive circuit logic error

(3) poor discharge of selenium drum components

(4) the signal wiring is not connected properly

inspection parts and maintenance methods:

(1) first replace the selenium drum assembly to see whether the fault disappears. If so, it indicates that it is the problem of the selenium drum assembly, and then replace it. The whole page is completely black, indicating that the laser is definitely good. Therefore, you can replace a new toner drum and reprint it. If the fault is eliminated, it is enough to prove that there is a problem with the toner drum assembly. At this time, you can check whether the charging electrode of the photosensitive drum, the bias electrode of the magnetic roller and the elimination electrode of the photosensitive drum are in good contact. If there is any bad contact, you should find and repair it

(2) then check whether the charging electrode wire is short circuited or in poor contact with the grid. If so, replace, repair or clean it. We know that most of the selenium drum components have different structures due to different models, but their working principles are the same. For the selenium drum charged with electrode wire, if the insulating base of electrode wire is burnt, the resistance gear of multimeter can be used to measure the resistance between electrode wire and grid to see whether it is short circuited. If it is short or the resistance is very small, clean or replace the insulating base. In addition, electrode wire pollution or displacement can also cause this fault, so it is necessary to clean or correct the electrode wire

(3) if the above checks are in good condition, the fault may be the laser high-frequency drive circuit or logic circuit in the scanning component. Check whether the scanning logic circuit is damaged and replace the scanning component

(4) sometimes because a printer is connected with multiple computers, the signal line is often unplugged (we are opposed to using a signal line to connect multiple computers, because it will easily cause damage to the signal pin and socket), and the signal line is damaged or cannot be plugged firmly, so that some signals cannot be transmitted, and then the fault of outputting all black samples will be caused, So before checking, you can check whether the signal line is complete, and China will host this year's APEC summit and plug it in, so as to avoid other unnecessary maintenance

2 output full width longitudinal black belt (line)

possible fault causes:

(1) the photosensitive drum scraper is damaged or the sharp object on the scraper scratches the photosensitive drum

(2) local damage of magnetic roller scraper

(3) the printer (general guide tray channel) is contaminated with toner

general maintenance methods:

(1) first observe whether the black belt of the output sample is fuzzy. If so, clean or replace the photosensitive drum scraper. If not, check whether there are scratches on the drum longitudinally. If there are, check whether there is damage on the scraper of the drum. Generally speaking, there are longitudinal black lines on the output sample, which indicates that there are obvious scratches on the drum longitudinally (circumferential direction). This can only replace the drum, but also carefully check whether the cleaning scraper is sticky or damaged. Remove or replace the scraper first to avoid scratching the drum again

(2) if it is not the problem on the photosensitive drum, you can check whether there are foreign objects or defects on the magnetic roller scraper, so that it cannot limit the role of toner. There is no jumping imaging distance between toner and the photosensitive drum, and the toner on the local magnetic roller is directly adhered to the surface of the photosensitive drum, forming a black line. The solution to continuously improve the innovative carrier of the new material industry is to clean the scraper on the magnetic roller or replace the scraper on the magnetic roller

(3) in addition to the above two reasons, the printer (generally the guide tray channel) will also form a black bar fault if it is polluted by toner. When molten toner accumulates on the paper guide in the paper path of the printer, and the printing paper rubs against the printing paper as it passes, a black line will be formed. The black line formed by this reason generally changes in intensity, and the edge of the line is fuzzy, which is not as clear as the above two reasons. Most of the channels polluted by toner are conveyor wheels, upper and lower hot rollers, etc., so it is necessary to remove them. This can be done by removing these dirt while hot when turning off the printer power. However, if it is caused by the damage or aging of the upper and lower hot rollers, the problem will be solved temporarily after cleaning, but the fault will reappear immediately. Therefore, it should be considered to replace the upper and lower hot rollers

3 output horizontal irregular black belt (line)

possible fault causes:

(1) poor contact of photosensitive drum elimination electrode

(2) the shear force of the photosensitive drum scraper is too large

(3) jitter occurs when the main gear of the photosensitive drum rotates

(4) the photosensitive drum is defective or installed incorrectly

general maintenance methods:

(1) first check whether the contact point of the photosensitive drum is in good contact, the lattice of the exposed photoconductor on the surface of the photosensitive drum is connected with the conductive base, and the charge is released to the ground through the conductive base of the photosensitive drum and the extinction brush. For example, the eliminator brush of HP 4L and 4P photosensitive drums adopts the power dissipation method of friction between the eliminator brush and the inner wall of the conductive base cylinder. After a certain period of time, the inner wall of the photosensitive drum is grinded into two deep grooves (double electric shock) by the eliminator brush, which will cause poor contact between the contact and the conductive base of the photosensitive drum. The maintenance method is to change the original friction track of the contact, and then apply conductive grease to increase the conductivity

(2) check whether the photosensitive drum scraper is lubricated (whether the shear force is too large). The micro Vickers hardness test between the cleaning scraper and the photosensitive drum is also used for the test of very small or very thin parts. There is a shear angle between them, which has a great shear force on the photosensitive drum. In order to have good cleaning ability between the photosensitive drum and the scraper, and also need good lubrication without damaging the photosensitive drum, a layer of lubricating powder is coated on the blade of the scraper. When the friction of the long-term lubricating powder disappears or the lubricating powder is wiped off when it is cleaned, the scraper will form a great shear resistance to the photosensitive drum, so that the photosensitive drum will not run smoothly and shake (this usually occurs on the regenerated selenium drum), which will make the photosensitive drum not rotate smoothly and cause failure. Therefore, special attention should be paid to not removing the lubricating powder from the scraper when cleaning or replacing the photosensitive drum. To eliminate this fault, only replace the scraper

(3) there are many transmission gears in the printer. When the printer is used for a certain period of time, there are often problems of no lubrication and excessive wear between the transmission gears, resulting in excessive meshing clearance between the gears, causing unstable transmission and shaking, which is also an important reason for the horizontal black line fault. At this time, it is necessary to adjust the main drive gear engaged by the photosensitive drum first, and add some lubricating paste or oil on the gear appropriately. If the wear is severe and cannot be adjusted, the main drive gear engaged by the printer and the photosensitive drum should be replaced in order to eliminate the fault

(4) another reason for horizontal black lines is that the photosensitive drum is defective or incorrectly installed. When the photosensitive drum is defective, most of the horizontal black lines or stains on the printed page are regular. At this time, take out the selenium drum and check it carefully. If there is a problem with the photosensitive drum, replace the photosensitive drum. If there is no problem with the photosensitive drum, it may be caused by the incorrect installation of the photosensitive drum. When the photosensitive drum is installed incorrectly, it will cause abnormal contact with the printing paper, uneven printing and black stripes. At this time, open the cover of the printer box, take out the photosensitive drum and reinstall it correctly