If the linear module can only move in one direction, the issue is related to the end-stop switch.
When the carriage/slider of the issue linear module is stuck and cannot move to another direction, use a USB cable to connect the machine to the computer.
In Luban console, input M119.
If the X linear module can only move in one direction, the X_min or X-max may show TRIGGERED.
Similarly, if Y or Z linear modules can only move in one direction, please check whether y_min, y_max, z_min, or z_max show TRIGGERED.
Please follow the below step to fix the end-up switch.
1. Dismantle the cover without a cable end of the issue linear module. You may need the 2.5 & 2.0 hex screwdriver.
2. Here is the end-stop switch.
3. Check if the end-stop switch is stuck.
4. Use something to touch the end-stop switch and assemble the linear module to check whether it works.
If the tips above cannot help, please send an email to support@snapmaker.com