If your printer displays a homing failed error message while trying to start a print or when you navigate to Prepare > Auto Home, that means that your printer is trying to home but certain components aren't being detected. This could be caused by an endstop failing to trigger or respond, or your BLTouch pin didn't drop/trigger. Additionally, if one of your motors are disconnected, this can also cause this error message.
Here are some possible fixes to this problem:
- Make sure to check all motor wires to ensure that they are properly connected.
- Make sure that the BLTouch pin drops as well. If the BLTouch pin isn't visible in the retracted position, then it could've broken off while printing and you need to replace it.
- Make sure that the BLTouch light turns on when the machine powers up. If the BLTouch fails to turn on, use this post to help figure out why.
- Test the endstops and make sure that a red light turns on when pressed. If there is no red light, then they may be damaged or not connected properly.