X Axis Humming Noise on 3D Printer a350

Hi all,


The limit switch works.

I’m reaching out to the community for some help and advice. Has anyone else experienced this issue before? If so, what steps did you take to resolve it? Any suggestions would be greatly appreciated.

Thanks in advance!

The limit switch, indeed, is not working in the provided video. The noise is the stepper motor skipping steps as it physically cannot go past the end and is just crunching against the limit switch. If the limit switch was working, it would tap it, move back a few mm, then slowly tap it again. You can test swapping it with one of the modules on the Y axis, but I would suggest contacting support to get a new limit switch.

EDIT: If the limit switch works outside of the linear module, then the control board in the module is likely having problems and you’ll need a new linear module. Maybe the wires from the limit switch to the control board have a break? Try tapping the limit switch while the machine homes.

Even though we took it apart and tested the limit switch with a breadboard, it is indeed not working when we press it manually to try to stop it while homing. I’m starting to think it has to be a problem with the control board. We just tested it again with the breadboard tester.

Looking at this image:

It looks like the limit switch just plugs into the mainboard at the other end. Which should make it quite easy to test with a continuity test. The red box is showing the heat dissipation pad on the stepper driver, but I assume the black and white wires are to the limit switch at the other end.

EDIT: Yes, they are for the limit switch as stated in the video here:

Looks like the wires and switch are good, so I’d lean towards the control board being bad. Check the solder joints for the limit switch plug on the board?