Fault-free repair for laser printers

Fault repair for laser printers

Fault symptom 1:

After using an HP LaserJet 1010 laser printer for a period of time, when online printing is performed, the paper feed is normal, but no handwriting is printed.

Analysis and maintenance:

We know that HP LaserJet 1010 laser printer is currently a unique HP instantaneous splitter technology, up to 12 ppm (A4, letter) printing speed; with the HP Resolution enhancement technology (RET), the resolution is as high as 600 dpi; the monthly printing load is as high as 5,000 pages, the main product of 8 mb ram, in today's Party and government organs, large and medium-sized enterprises and institutions, financial and securities services, and other fields all occupy a certain proportion.

Next, based on the fault, the author first checks whether the computer and its peripherals (such as printing cables, printer connection ports, power outlets, etc.) are normal. If no exception exists, the fault of the computer and its peripheral hardware can be preliminarily ruled out, so it is determined that the fault is caused by the HP Laser printer itself. The printed text is completely absent and can be excluded one by one according to the following steps:

1. Replace the new powder box to see if the fault disappears. Check whether the toner seal is pulled out and whether the toner is used up before replacement. If the seal is not pulled out or the toner is used up, it will cause no handwriting. However, if the toner used up in the powder box fails, the output sample gradually fades in the middle of the vertical section, the red indicator lights flash constantly, prompting you That the toner in the powder box is about to run out. It is rare to print all handwriting, and it takes a long time to fade the image. Therefore, the reason why there is no toner in the powder box is basically ruled out.

2. Check whether the toner cartridge of the HP Laser printer is faulty. Check carefully and find the toner marks on the surface of the toner cartridge, so it is determined that there is no fault in the printer developing parts. The problem lies in the handwriting transfer from the toner cartridge to the paper.

3. Check the electrode wire on the transfer electrode assembly and find that the electrode wire does not melt off, but there are a large number of black flags attached to the front and back of the electrode wire, in this way, it is determined that the fault is caused by a large number of charged powder leaks, which causes the electrode wire to fail to discharge normally, or the discharge voltage is too low. Therefore, it is impossible to adsorpate the developing toner with negative power to the paper, this causes no handwriting on the printed paper.

The solution is to dip a small group of clean cotton into a small amount of methyl ethyl ketone and gently wipe it off to clear the toner around the electrode wire on the transfer electrode assembly. After cleaning, use a small batch of cotton dipped in a small amount of anhydrous alcohol to wipe it again. After the alcohol evaporate, re-install it in place. Start the system and print the text normally. The fault will be rectified immediately.

Fault symptom 2:

An Epson laser printer, after the boot, the self-testing run time is significantly longer, after the completion of the display "mob5", all the green indicators are off, online do not print.

Analysis and maintenance:

The automatic check operation indicates that the mechanical part of the laser printer is normal. After power-off, turn on the chassis to check toner cartridges and toner. No exception is found. According to the fault that the self-check operation time is too long after the startup, It is preliminarily determined that the fault may be related to the paper path fault. Because there is no ready-made circuit diagram and related information in the machine in the hands, we can only check the physical diagram of the laser printer one by one based on previous maintenance experience. One by one, we found that the machine has only one circuit sensor, when the sensor is removed and measured with A multimeter ohm, it is found that the resistance value of the sensor is extremely unstable when it is not operated. It is determined that the sensor is the cause of abnormal printer operation.

Because it is difficult to buy such sensors of the same model on the market, it is best to fix them. Take care of the sensor and find that the internal contact parts have been severely oxidized for a long time. First, use a tool knife to carefully scrape the surface oxide layer, then pour a little anhydrous alcohol repeatedly cleaned several times, take out and slowly dry with a hair dryer at a low temperature, then the original assembly in place (because its volume is only a few millimeters, the assembly process should be very careful to avoid damage to the hook and loss of spring ). Finally, the sensor is loaded into the laser printer and then re-started for trial run. Online printing is normal and troubleshooting.