The hottest printer output fault and solution solu

2022-08-10
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Printer output faults and solutions solution III

the laser printer has been used for more than a certain number of years, that is, after outputting a certain number of samples, its printing quality will decline, and when some parts are used to the limit, there will be printing quality defects. Some are because the operator is not familiar with the working principle and performance of the laser printer, so it is not adjusted to the best state or is still in the wrong state during operation, and the materials used do not conform to the regulations, resulting in poor output effect, which is called "not a fault". It generally does not affect the work of the printer, but the printed results are not satisfactory. Next, we will continue to introduce several solutions to print quality problems

7. What about light white output

possible fault causes:

(1) the printing paper is damp; (2) The toner is damp or there is a problem with the drum assembly; (3) After exposure, the photosensitive drum has poor power dissipation and low surface potential; (4) Insufficient exposure; (5) Low magnetic roller bias; (6) The transfer voltage is low

general maintenance methods:

(1) change the dry printing paper for printing. If the fault disappears, it indicates that the printing paper is damp

(2) try the output effect with a good ink cartridge. If the fault is eliminated, it indicates that there is a problem with the toner. You can replace the dry toner. If not, replace the photosensitive drum assembly and print the test sample. By observing that the experimental force that the test sample can bear is as small as a few 10 centinewtons (such as spandex fiber for textile), the location of the fault is judged. Damp drum assembly is also an important reason for light image color

(3) if the first two reasons are not the same, it may be that the charging electrode of the photosensitive drum and the electrode of the transfer roller are in poor contact or have problems. The following methods can be used to determine the location of the fault

the method is: reprint the test sample, stop the machine manually halfway, take out the photosensitive drum assembly and the final fixing test sample, and observe the toner image on the photosensitive drum surface and the test sample. First observe the toner concentration on the surface of the drum. If the ink concentration is insufficient, there are three reasons: the charging voltage of the drum is low; Poor power dissipation and small potential difference of photosensitive drum; The magnetic roller toner bias voltage is too high

if the toner concentration on the surface of the photosensitive drum is normal, generally, mineral oil with medium viscosity is used and the toner concentration on the test sample is not enough, indicating that the surface of the transfer roller is polluted or the transfer voltage is low. Check whether these parts are in good contact and free of pollution, and remove them

(4) the toner image on the surface of the photosensitive drum is not thick and the test sample has a bottom ash, which indicates that the charging voltage on the surface of the photosensitive drum is low or the photosensitive drum is seriously worn. It is necessary to clean the charging electrode wire (charging roller). If the problem cannot be solved, check the high voltage generating circuit or replace the high voltage board. The high-voltage circuit and power control circuit of some models are integrated, which can be checked and repaired by measuring the boost components

(5) when the above checks are in good condition, check whether the magnetic roller has bias voltage. At this time, adjust the print concentration knob and observe whether the toner image on the photosensitive drum changes. The toner image changes, indicating a development bias; There is no change in the toner image, which may be due to poor contact of the adjustable potentiometer or non-magnetic roller bias. The concentration adjustment potentiometer can be cleaned or repaired

(6) if the charging voltage and magnetic roller bias voltage are normal, check whether the laser driving current is weakened. Clean the lens and reflector in the assembly first. After the clearance between the 1st and 2nd leaf spring plates is maximum, if the image is still shallow, check whether the extinction electrode of the photosensitive drum has poor contact. If the extinction electrode contacts well, it may be that the laser is aging or the laser beam current is low. Open the scanning component and adjust the laser beam current. Note that adjusting the laser beam current (except for the laser beam current offset caused by the change of line components) may accelerate the aging or damage of the laser, and should be adjusted by an experienced repairman

(7) if the toner image on the surface of the photosensitive drum is normal after the above inspection, and the toner concentration on the test sample is not enough, the transfer electric field intensity should be low. Check whether the transfer electrode wire (transfer roller) is polluted or in poor contact, and clean it. If it is the model of electrode wire transfer, check whether the position of electrode wire is correct. If the above parts are normal, check the transfer high voltage generating circuit

8. What about the false output image

possible causes of failure:

(1) printing paper that does not meet the standard is used; (2) The toner model does not match the model or the toner is damp; (3) The photosensitive drum is damp; (4) Loose parts in the scanning assembly; (5) The scanning motor runs unsteadily and jitters

general maintenance methods:

(1) change the printing paper with better quality to print. Due to static electricity, the output text is blurred or there is a virtual frame around the text. It is common to see it in the tensile test of category 1 when using film printing, mainly because when the film with static electricity contacts the photosensitive drum for transfer, the static electricity will repel the toner and make the toner move towards the edge of the font, and the whole film will cling to the photosensitive drum under the action of the transfer electrode, resulting in a faint circle of toner on the edge of the font. It can be solved by using the film after eliminating static electricity

(2) the mismatching or damp toner model is also an important reason for the false output font. Replace the toner corresponding to the printer model, and pay attention to keeping it dry during storage and use, and do not get damp

(3) when the photoconductive material on the surface of the printer drum is damped, the photoconductivity becomes poor, and the potential difference after exposure will be very uneven. When developing, the toner cannot be normally adsorbed to the drum, which will also make the image toner unevenly distributed, causing the image to become shallow or blurred. At this time, the failure can be eliminated by drying the photosensitive drum with an electric hair dryer

(4) the fixed card of the lens in the scanning assembly is loose, which will make the lens jitter, resulting in poor focus and the formation of dot matrix latent image. Check whether the component fixing card in the assembly is loose and fix it firmly again

(5) the scanning rotating mirror is directly fixed on the motor shaft, and the motor bearing is worn. When the motor rotates unsteadily, the scanning rotating mirror will also shake, making the exposure dot matrix virtual. When the motor rotates, excessive centrifugal force will produce vibration, which will also cause the whole image to be blurred. This is generally the case when the printer hears a vibrating sound when printing. The maintenance method is to disassemble the scanning components for inspection. If the gap between the motor shaft and the bearing is too large, it can be adjusted slowly until the output quality is satisfactory. To ensure accuracy, it is best to replace the scanning motor or scanning component with a new one. (to be continued)

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