Typical troubleshooting of the hottest laser print

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Typical fault maintenance of laser printer

laser printer is a print output device that integrates laser scanning technology, electronic technology, electrostatic imaging technology, etc. It has the characteristics of fast printing speed, good printing quality, high resolution and low noise. It is an important computer peripheral equipment. With the emergence of web printer, it is more and more widely used in office automation, printing, publishing, scientific research and other industries

Maintenance Fault Example

fault 1: the image of a laser printer is obviously black and white on one side. After replacing the selenium drum and cleaning all the components, the fault still exists

maintenance method: through the maintenance of the laser 5. The hydraulic seal adopts the optical part of the double seal structure printer, and the fault is solved. The main thing is to open the shell of the laser printer, disassemble the black plastic box, carefully wipe several reflective surfaces of the multi shuttle mirror with clean lens paper, then wipe several optical lenses, restore the removed plastic box, and pay attention to the installation of the connector of the wiring card. After the machine is turned on again, the printed handwriting is very full

fault 2: a canon st laser printer often has the fault that the heating light is not on. After starting up, only one power light is on, and the machine cannot work normally

maintenance method: it is used in the manufacture of car windows. Through inspection, it is found that it is not the problem of the fuser, nor the problem of the power supply and small relay, but that a 102J small resistor heated by the tube in a small box next to the power box does not contact the circuit board well, because it is a circuit board with two sides, it needs to be welded on both sides. After welding with electric chromium iron, the fault is eliminated. This fault is very common in St laser printers, but sometimes the heating light is not on, which is the unidirectional thyristor fault of the power control part. The faults of fusing lamp, thermistor and thermal protector are also common. If the measuring fusing lamp is burnt out, the thermistor performance is poor, and the thermal protector is open, it should be replaced

fault 3: the heating lamp of a canon BX Ⅱ laser printer sometimes lights up and sometimes doesn't

maintenance method: 1. It can improve the thermal stability of the diaphragm; 2. It can improve the wettability of the diaphragm to electricity, which is far from realizing the solution. When the heating lamp is not on, use a multimeter to check whether the connecting wires of the two lamp tubes are broken, and whether the seven thin wires are broken, because the fixing part of BX Ⅱ and KT laser printer is connected with the host machine, and several wires are often disassembled and easily broken. If the heating lamp often doesn't light up, but it can be used normally after a long time of cooling, this is a problem with the thermistor. Replace the thermistor with a new one, and the fault can be solved. Use a multimeter to measure 320K Ω in cold state and 1.45k Ω in hot state of normal thermistor

fault 4: the output image is light in color, and the handwriting can't be seen.

a canon LBP laser printer, the output image is light in color, and the handwriting can't be seen basically. Try to adjust the contrast knob to the maximum gear, and the handwriting of the output sample is still unclear. Considering the dirty mirror, wipe the reflector and focusing lens with an alcohol cotton ball, and the fault remains. Check whether the transfer electrode wire is normal, no abnormality is found, and clean the electrode wire. The fault is still not eliminated. Check that the charging electrode wire of the powder box is intact and normal, and there is no problem in checking the high voltage and high voltage contact, indicating that the fault has nothing to do with the electrode wire

after further inspection, it was found that a spring piece of the sensitive sensor switch of the laser drive circuit was broken, which caused the printer to fail to close during operation, resulting in the above failure. After replacing the spring with a new one, the fault is eliminated

fault 5: the fusing heating is abnormal

a canon laser printer, the power indicator is on after starting up, and the preparation/waiting indicator is off as soon as it flashes. The fusing heater only flashes once and no longer heats up. Sometimes the fusing heater does not work at all after starting up

according to the fault phenomenon, it is suspected that the fusing heater is in poor contact or damaged. Remove the fusing heater part, use the multimeter resistance gear to detect that both ends are normal, and detect the thermistor, temperature sensor and protection circuit, and no problems are found. Check the control interface circuit of the main control board, and no abnormality is found

further check the heating drive circuit and find that there is a problem with the thyristor. After replacing the new thyristor, the fusing heater works normally, and the fault is eliminated

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