1. Printer output blank paper
For needle printers, the reasons for blanking of printing paper are mostly due to drying of ribbon ink, broken ribbon, damaged print head, etc., and the ribbon should be replaced or repaired in time; for inkjet printers, the failures that cause blank printing are mostly due to clogged nozzles, no ink ink in the ink cartridge, etc., so the nozzle should be cleaned or replaced ink cartridges; for laser printers, the reason for this type of failure may be that the development roller does not absorb toner (the DC bias of the development roller has not been added), or the photosensitive drum is not grounded, so that the negative charge cannot be released to the ground, and the laser beam cannot function on the photosensitive drum.
In addition, if the photosensitive drum of the laser printer does not rotate, no image will be generated and transferred to the paper. Disconnect the printer power, remove the toner cartridge, open the notch on the lid, mark the non-photosensitive part of the photosensitive drum and reinstall it into the machine. After turning on the computer and running for a while, then take out and check whether the mark has moved to determine whether the photosensitive drum is working properly. If the toner cannot be supplied normally or the laser beam is blocked, blank paper will also occur. Therefore, check whether the toner is used up, whether the ink cartridge is properly loaded into the machine, whether the sealing tape has been removed, or whether there is any obstruction on the laser irradiation channel. It should be noted that the power must be turned off during inspection, as the laser beam may damage the operator's eyes.
2. Print paper output turns black
For needle printers, the causes of this failure are hair removal of ribbons, too much ink on ribbons, dirty printheads, poor quality of ribbons and too close to the push rod position. During maintenance, the position of the push rod should be adjusted first. If the fault cannot be eliminated, then replace the ribbons and clean the printhead, which can generally be eliminated. For inkjet printers, it should be focused on checking whether the nozzle is damaged, whether the ink pipe is broken, and whether the ink model is normal. For laser printers, it is mostly due to the failure of the corona discharge wire or the failure of the control circuit, which causes the laser to be emitted, causing the print output to be completely black. Therefore, it should be checked whether the corona discharge wire is disconnected or whether the corona high voltage exists, and whether the beam detector in the laser beam path is working properly.
3. Incomplete or unclear characters are printed
For inkjet printers, there may be two reasons: the ink cartridge is exhausted, the printer is not used for a long time, or is directly exposed to sunlight, resulting in the nozzle blockage. The solution is to replace the ink cartridge or ink. If the ink cartridge is not used up, it can be concluded that the nozzle is blocked: remove the ink cartridge (for a printer that is not an integrated printer, the nozzle needs to be removed), soak the nozzle in warm water for a while, be careful not to immerse the circuit board part in water, otherwise the consequences will be unimaginable.
For needle printers, there may be the following reasons: the printing ribbon is used for too long; the print head has not been cleaned for a long time, and there are too many dirt; the print head has a broken needle; the print head driver circuit is faulty. The solution is to first adjust the distance between the print head and the printing roller. The fault cannot be eliminated. You can change the ribbon. If it doesn't work, you need to clean the print head. The method is: remove the two fixing screws on the printhead, take off the printhead, use a needle or a small hook to remove the dirt in front and back of the printhead, generally the ribbon fiber accumulated for a long time, etc., and then drop a few drops of instrument oil in the back of the printhead to remove some dirt. If the ribbon is not installed, a few pieces of paper are pressed, and then install the ribbon. This problem can basically be solved. If the printhead is broken or the driving circuit problem is problematic, you can only replace the printing needle or driving tube.
4. Printing handwriting is light
For needle printers, the causes of this type of fault are mostly dry ink of ribbon, broken needle of the print head, and adjusting the push rod too far. They can be solved by replacing the ribbon and adjusting the push rod; for inkjet printers, blocked nozzles, ink too dry, incorrect ink model, air inlet in the ink pipe, and too high working temperature of the printer will cause this fault. The nozzle, ink cartridge, etc. should be tested and repaired; for laser printers, when there is less toner in the toner cartridge, the development voltage of the development roller is low, and the toner photosensitive effect is poor, it will also cause the printing handwriting to be light. At this time, remove the toner cartridge and shake it gently. If the printing effect does not improve, you should replace the toner cartridge or adjust a set of photosensitive switches under the printer toner cartridge to match the photosensitive sensitivity of the toner.
5. When printing, the handwriting is clear on one side but not on the other side
This phenomenon generally occurs on needle printers, and inkjet printers may also occur, but the probability is small, mainly because the print head guide rail is not parallel to the printing roller, resulting in the distance between the two being far and near. The solution is to adjust the spacing between the print head rail and the printing roller so that it is parallel. The specific method is: loosen the adjustment sheets on both sides of the print head rail, rotate the adjustment sheet counterclockwise to reduce the gap, and finally adjust the print head rail and the print roller to parallel to solve the problem. However, you should pay attention to adjusting the right direction when adjusting. You can adjust it gradually and print it a few more times.