After prolonged use, dust may accumulate inside the offset measurement switch of Kobra 2 Pro. The accumulation of dust can create an insulating layer between the connectors or circuits on the PCB board, resulting in poor contact. This situation may lead to the following error prompts during module calibration or automatic leveling process: “The module is abnormal.Please calibrate the position of the nozzle and module”.
The image below shows the separately removed offset measurement module, where ① and ② correspond to the adjustment screws.
● Phillips screwdriver
● M2.0 Allen key
● lint-free cloth
● open-end wrench
PS: Some images do not show the Y-axis vibration sensor not because it has been removed, but because we used images from the Kobra 2. Thank you for your support.
Before performing any maintenance, make sure to turn off the printer and disconnect the power for safety.
First, remove the PEI spring steel from the Heated bed. Then, locate the holes for the fixed offset measurement module behind the aluminum Heated bed. Use an M2.0 Allen key wrench to loosen the screws and remove the offset measurement module. After that, unplug the connections of the offset measurement module and the Y-axis vibration sensor.
Hold the offset measurement module casing with the other hand and gently pry it open using a Phillips screwdriver inserted into the gap of the connector. (Note: There are two small springs inside, pressing the casing with your hand will prevent the springs from bouncing off during disassembly.)
Use an M2.0 Allen key to loosen the side screw of the offset measurement module. Press the offset measurement switch and remove it.
Use a Phillips screwdriver to remove the self-tapping screws that secure the front and back PCB boards. Carefully take out the two PCB boards to avoid disconnecting any wires.
Use a lint-free cloth to wipe the marked areas in the image, including the contact pins and metal pieces.
First, Assembly the front PCB board (Note: The metal piece should face downward during Assemblyation) and align it with the screw holes on the plastic part before tightening the screws. Then, Assembly the back PCB board. To facilitate Assemblyation, reverse and press down the offset measurement switch. The Assemblyation method is the same as before.
Assembly the offset measurement switch, aligning the side screw with the groove on the plastic part, and tighten the screw appropriately to ensure the height of the screw does not obstruct Assemblyation. Assembly the terminal PCB board, making sure it aligns with the corresponding groove on the plastic part. Finally, put the two springs back and Assembly the offset measurement module casing.
Reconnect the wiring and use an M2.0 Allen key to tighten the two screws that secure the offset measurement module. Finally, Assembly the PEI spring steel.
Use an M2.0 Allen key to tighten the screws behind the module in a clockwise direction. Apply slight upward force on the wrench during tightening to ensure that the module button is in the highest position.
Loosen the side screws of the module (about half to one full turn) to allow the button to pop up. Observe whether the button height is higher than the platform (if it is lower, check the tightness of the side screws). Then, place an open-end wrench directly above the offset measurement switch with the fixture edge against the edge of the heat bed. Press the wrench on the middle of the stainless steel button. Press the wrench in the middle and use an M2.0 Allen key to tighten the side screws of the module clockwise (the Allen key should not apply pressure up or down on the screws).
After tightening the screws behind the module (half to one full turn), gently press the button to see if it smoothly depresses and rebounds. If not, slightly loosen the screws behind the module until the button can depress and rebound normally.
Place the open-end wrench on the platform surface and move it left and right to check for any interference between the open-end wrench and the upper surface of the module button. If there is interference, it means the button is too high, and you need to repeat steps 1, 2, and 3 until there are no interference points. From the side, observe if there is a gap between the top surface of the module button and the bottom surface of the fixture. If there is a gap, it indicates that the module button needs further adjustment. Repeat steps 1, 2, and 3 until there are no interference points.
The above troubleshooting methods did not resolve the issue. It is recommended that you create an after-sales work order to feed back the process and results of the previous inspection to the after-sales engineer. After-sales engineers will help you solve the problem.