Two cases of laser printer failure repair
Fault phenomenon 1:
After using an HP LaserJet 1010 laser printer for a period of time, the paper feeds normally when printing online, but there is no text print.
Analysis and repair:
We know that HP LaserJet 1010 laser printer is currently a product that uses HP's unique instantaneous hot melt technology, with a printing speed of up to 12 ppm (A4, letter); an HP resolution enhancement technology (REt) is used, with a resolution of up to 600 dpi; a monthly printing load of up to 5,000 pages, and an 8 MB RAM main product, which accounts for a certain proportion in today's party and government organs, large and medium-sized enterprises and institutions, financial and securities services, etc.
Next, based on the fault phenomenon, the author first checks whether the hardware part of the computer and its peripherals (such as printing cables, printer connection bayonets, power sockets, etc.) to check whether it is normal; if there is no abnormality, the hardware failure of the computer and its peripherals can be initially eliminated, so it is determined that it is caused by the failure of the HP laser printer itself. There is no print trace, and you can exclude it one by one according to the following steps:
1. First replace the new powder box and see if the fault disappears. When replacing, you should first check whether the toner seal strip is pulled out and whether the toner has been used up. If the sealing strip is not pulled out or the toner has been used up, the wording will be gone; but if the toner in the powder box is used up, the output sample will gradually fade, and the red display light will keep flashing and alarming, indicating that the toner in the powder box in the machine will be used up. The phenomenon of no print marks is very rare, and it must take a long time after the image becomes lighter, so the reason why there is no toner in the powder box is basically ruled out.
2. Then check whether the HP laser printer cartridge is malfunctioning. A careful inspection revealed that there were traces of toner on the surface of the toner cartridge, so it was determined that the printer development component was not malfunctioning. The problem was in the transfer of the handwriting from the toner cartridge photosensitive drum to the paper.
3. Finally, check the electrode wire on the transfer electrode assembly and found that the electrode wire has not fused and fallen off, but there are a large amount of black leakage powder attached to the front, back and left and right of the electrode wire. It is determined that the fault is caused by a large amount of charged leakage powder, which causes the electrode wire to fail to normal corona discharge, or the corona discharge voltage is too low, so the negatively charged development toner cannot be adsorbed on the paper, resulting in no word marks on the printing paper.
The solution is to dip a small ball of clean cotton into a small amount of methyl ethyl ketone, gently wipe it off when the machine is turned off, and remove the toner around the electrode wire on the transfer electrode assembly. After cleaning, wipe it with a small ball of cotton dipped in a small amount of anhydrous alcohol and wipe it again. After the alcohol evaporates and then reinstall it. When you start the computer, the printed text is normal, and the fault is immediately eliminated.
Fault phenomenon 2:
An Epson Epson laser printer has significantly longer operation time when it is tested by itself after turning on. After completion, it displays "MOB5" and all green indicator lights are turned off and no printing is made online.
Analysis and repair:
The power-on operation can be performed by self-testing, indicating that the mechanical part of the laser printer is basically normal. After the power is off, open the case and check the toner cartridge and toner in turn, and no abnormalities are seen. Based on the fault phenomenon of the self-test running time after starting the machine, the preliminary judgment may be related to the paper circuit fault. Because I did not have the ready-made circuit diagrams and related information of the machine, I could only check the actual image of the laser printer one by one based on my previous maintenance experience. When I checked one by one, I found that the machine had only one circuit sensor. I removed the sensor and used the ohmic gear to measure it with the multimeter. I found that the resistance value of the sensor was extremely unstable when it was not working. This determined that the sensor was the reason for the abnormal operation of the printer.
Since it is difficult to buy this type of sensor on the market, it can only be repaired. Carefully disassembled the sensor and found that its internal moving contact parts had severely oxidized due to the long service life. First, use a tool knife to carefully scrape off the surface oxide layer, then pour in a little anhydrous alcohol and wash it repeatedly several times. After taking it out, use a hair dryer to slowly dry it at low temperature, and then assemble it in place as it is (because it is only a few millimeters in volume, you must be very careful during the assembly process to avoid damaging the lock hook and losing the spring). Finally, the sensor is installed into the laser printer and rebooted and tested. The online printing is normal and the troubleshooting is solved.
Fault phenomenon 1:
After using an HP LaserJet 1010 laser printer for a period of time, the paper feeds normally when printing online, but there is no text print.
Analysis and repair:
We know that HP LaserJet 1010 laser printer is currently a product that uses HP's unique instantaneous hot melt technology, with a printing speed of up to 12 ppm (A4, letter); an HP resolution enhancement technology (REt) is used, with a resolution of up to 600 dpi; a monthly printing load of up to 5,000 pages, and an 8 MB RAM main product, which accounts for a certain proportion in today's party and government organs, large and medium-sized enterprises and institutions, financial and securities services, etc.
Next, based on the fault phenomenon, the author first checks whether the hardware part of the computer and its peripherals (such as printing cables, printer connection bayonets, power sockets, etc.) to check whether it is normal; if there is no abnormality, the hardware failure of the computer and its peripherals can be initially eliminated, so it is determined that it is caused by the failure of the HP laser printer itself. There is no print trace, and you can exclude it one by one according to the following steps:
1. First replace the new powder box and see if the fault disappears. When replacing, you should first check whether the toner seal strip is pulled out and whether the toner has been used up. If the sealing strip is not pulled out or the toner has been used up, the wording will be gone; but if the toner in the powder box is used up, the output sample will gradually fade, and the red display light will keep flashing and alarming, indicating that the toner in the powder box in the machine will be used up. The phenomenon of no print marks is very rare, and it must take a long time after the image becomes lighter, so the reason why there is no toner in the powder box is basically ruled out.
2. Then check whether the HP laser printer cartridge is malfunctioning. A careful inspection revealed that there were traces of toner on the surface of the toner cartridge, so it was determined that the printer development component was not malfunctioning. The problem was in the transfer of the handwriting from the toner cartridge photosensitive drum to the paper.
3. Finally, check the electrode wire on the transfer electrode assembly and found that the electrode wire has not fused and fallen off, but there are a large amount of black leakage powder attached to the front, back and left and right of the electrode wire. It is determined that the fault is caused by a large amount of charged leakage powder, which causes the electrode wire to fail to normal corona discharge, or the corona discharge voltage is too low, so the negatively charged development toner cannot be adsorbed on the paper, resulting in no word marks on the printing paper.
The solution is to dip a small ball of clean cotton into a small amount of methyl ethyl ketone, gently wipe it off when the machine is turned off, and remove the toner around the electrode wire on the transfer electrode assembly. After cleaning, wipe it with a small ball of cotton dipped in a small amount of anhydrous alcohol and wipe it again. After the alcohol evaporates and then reinstall it. When you start the computer, the printed text is normal, and the fault is immediately eliminated.
Fault phenomenon 2:
An Epson Epson laser printer has significantly longer operation time when it is tested by itself after turning on. After completion, it displays "MOB5" and all green indicator lights are turned off and no printing is made online.
Analysis and repair:
The power-on operation can be performed by self-testing, indicating that the mechanical part of the laser printer is basically normal. After the power is off, open the case and check the toner cartridge and toner in turn, and no abnormalities are seen. Based on the fault phenomenon of the self-test running time after starting the machine, the preliminary judgment may be related to the paper circuit fault. Because I did not have the ready-made circuit diagrams and related information of the machine, I could only check the actual image of the laser printer one by one based on my previous maintenance experience. When I checked one by one, I found that the machine had only one circuit sensor. I removed the sensor and used the ohmic gear to measure it with the multimeter. I found that the resistance value of the sensor was extremely unstable when it was not working. This determined that the sensor was the reason for the abnormal operation of the printer.
Since it is difficult to buy this type of sensor on the market, it can only be repaired. Carefully disassembled the sensor and found that its internal moving contact parts had severely oxidized due to the long service life. First, use a tool knife to carefully scrape off the surface oxide layer, then pour in a little anhydrous alcohol and wash it repeatedly several times. After taking it out, use a hair dryer to slowly dry it at low temperature, and then assemble it in place as it is (because it is only a few millimeters in volume, you must be very careful during the assembly process to avoid damaging the lock hook and losing the spring). Finally, the sensor is installed into the laser printer and rebooted and tested. The online printing is normal and the troubleshooting is solved.