How to repair the sensor of HP 1020 printer?

1, black printing appears on the white paper printed by the printer. Take a piece of white paper to print the test page. When the white paper comes out halfway, open the upper cover, take out the toner cartridge and carefully pull out the paper. If there are printing marks on the upper part of the paper, there is something wrong with the fixing assembly. If there is black printing on the lower part of the paper, it is only necessary to replace the toner cartridge (in many cases).

2. The paper jam is printed. Take 1020 as an example. Generally, there are sensors on the paper feeding channel to sense the direction of the paper, just like human nerve veins. Usually, there is one sensor on the back plate and two sensors on the fixed assembly. You can basically judge the problem by looking at the position of the paper card. If the paper is not fed for three times in a row, just replace the paper pick-up wheel. If there is no continuous paper feed, please observe whether the relay in the lower right corner of the machine sticks together.

3. There is no response when the printer is turned on. First, check whether the sensor on the backplane is normal. If it is normal, unplug the cable on the motherboard and see if the machine starts. If it can be started, it is a problem with the motherboard (just replace the motherboard). If it can't start normally, remove the power board and carefully observe whether the power board is burnt out (usually the switch tube is burnt out). Just replace the switch tube.

4, understand the working principle of the printer, plus qualified hands-on ability, clear the architecture of the printer. You are a qualified printer maintenance technician.