When you encountered this "Buildplate Continues to Press down The LCD After Reaching The Bottom" problem on your ELEGOO 3D printers, or the printer does not recognize the "home" position, please follow the instructions below:
Please check if there is a problem with the limit switch on the printer. In normal conditions, the indicator light will lights up like the picture below and there will be a buzzing sound when the build plate touches the LCD. If the limit switch can function properly, please go to step 2; If not, please reach out to our support team via firstname.lastname@example.org for some further advice.
Please print the "ChiTu Mainboard Specification" gcode file that comes with the original USB flash drive of the printer and then reset Z=0.
You can also download the corresponding original USB drive files from this link: https://www.elegoo.com/pages/3d-printing-user-suupport
Instruction on how to set Z=0: https://youtu.be/cqRBZUAEWD4
If the problem still can't be fixed after this method please go to step 3.
Please remove both the build plate and the resin tank then press the "home" button on the printer to check if Z-axis will stop or not when it reaches the bottom.
1) If the Z-axis can stop normally, it means that the limit switch can be triggered without any problem, but the limit switch stopper is too short to trigger the limit switch when the build plate is installed on the printer. You can put a 1-2mm spacer between the screws and the limit switch stopper as shown in the below pictures to fix this problem. (the limit switch stopper is at the bottom of the z-axis connecting shaft)
2) If the Z-axis does not stop even if you remove the build plate, it means the limit switch is damaged. Please take some pictures or a short video of the problem then send it to email@example.com with your order number, we will try our best to help.
Here is an instruction on how to replace the limit switch: