If there is a 'clunk' or 'pop' sound during the two Y-axes moving, please follow the below steps to do troubleshooting.

1. Power off the machine.
2. Dismantle the heated bed and platform from the two Y-axes.
3. Pull the sliders to the front end of the Y-axes manually.
4. Use one Laser module platform, and place it next to the two sliders.
   No gap between the sliders and the Laser platform. 
5. Power on the machine, and on the touchscreen, tap on Control and Home the printer. 
6. Control the Y-axes and let them reach their maximum distance. 
7. Check if there is a gap between the sliders and the Laser platform.

Here is a video guide: https://1drv.ms/v/s!Ai6rBxI_fDjYi0UEyKDU0O4v4Npu?e=jRieEB 

After you finish the test, please kindly send the test result to support@snapmaker.com. Our support team will help you out.