According to the order of photosensitive drum, cleaning part, developing part and fixing part, find out the cause of the failure.

(1) The photosensitive drum is scratched due to contact with other parts, or the surface of the photosensitive drum is damaged by friction due to excessive scraper pressure.

(2) The scraper is defective or there is too much powder on the scraper.

(3) The distribution of toner on the developing roller is uneven, and there are strips or sundries under the scraper. 4) The magnetic roller is dirty by striped carbon powder deposits.

(5) The entrance of the fuser is blocked, and the unfixed part after transfer rubs against the entrance of the fuser, damaging the image. (6) The surface of the heating roller is stained by dirt such as toner.

3. Causes of vertical white stripes:

(1) The photosensitive drum is badly scratched and toner cannot be printed.

(2) There is dirt on the charging electrode line, resulting in the corresponding part of the photosensitive drum being uncharged and white stripes appearing.

(3) Low power supply voltage causes uneven charging voltage, resulting in white stripes with different widths and unclear edges.

(4) The transmission electrode wire is too dirty to transmit normally. (5) Less and uneven toner or deformation of separation claw.

4. There is no image, and the paper is all black. Cause: The control circuit or scanning circuit may be faulty.

5. All-white image reason:

It includes an optical part, a charging part and a mechanical part.

(1) The laser or laser control circuit is damaged.

(2) The optical system is blocked by foreign objects; The mirror angle is wrong; The mirror is damaged or too dirty; Mirror aging.

(3) The scanning drive circuit is faulty, that is, there is no scanning.

(4) The charging electrode is damaged; Disconnect the charging electrode; Poor contact of transmission electrode or broken electrode wire.

(5) The transmission gear shaft rotates, but the wheel does not rotate, so that the photosensitive drum does not rotate.

6. Reasons for horizontal black stripes and white stripes:

(1) The two ends of the charging electrode wire are in poor contact, and the discharge sound can be heard, and a blank appears horizontally.

(2) The electrode wires used for charge transfer and charge elimination are too loose.

(3) The photosensitive drum rotates unevenly, and the drum shaft deviates from the center, resulting in uneven charging or transfer.

(4) The developing roller drives the clutch to rub or slip.

7. The reason why the printed image is dirty:

Regular image pollution often occurs in a certain part of the printed sample, which corresponds to the pollution or damage of the printer components. Irregular image pollution is often caused by irregular pollution.

(1) The surface of the photosensitive drum is polluted or scratched.

(2) Developing part: The solidified toner blocks stick on the developing roller, resulting in enhanced adsorption capacity.

(3) Cleaning part: the photosensitive drum cleaning device is damaged, especially the cleaning scraper is unbalanced or notched.

(4) The transfer electrode or charging electrode is not uniform left and right, resulting in uneven strip pollution.

(5) The rubber on the surface of the heating roller falls off or has scratches due to aging; Or the cleaning brush of the fixing roller is defective, so that the heating roller part is polluted by dust.

(6) Dust and caking are adsorbed on the surfaces of the thermistor switch and thermistor sensor of the fuser, resulting in increased friction, inaccurate temperature measurement and damage to the upper heating roller and thermistor sensor.

(7) The paper roller is polluted by toner, resulting in dirty printed images.

8. There are regular or irregular white spots on the black image.

(1) Regular white spots appear in the black part of the photosensitive drum due to peeling and scraping of the photosensitive layer.

(2) The developing bias is too high or the toner contains impurities. (3) Adjust and clean the transmission electrode wire.

(4) If the charging voltage is too high, it will catch fire when discharging, and the photosensitive drum will be broken or semi-broken, resulting in tiny white spots.

9. Causes of pollution on the back of printing proof:

(1) The toner leaks from the developer or cleaner and splashes on the paper path, resulting in the back of the paper being polluted.

(2) The poor cleaning of the heating roller makes the toner stick to the lower roller, which leads to the pollution of the back of the paper.

10. Fixed reason for deficiency:

(1) The fixing lamp tube is damaged or poorly contacted, and the heating wire is broken, resulting in inaccurate fixing temperature or low fixing temperature.

(2) The fixing heating roller is worn, and the surface is pitted, so the local fixing is not firm.