Hello, i have a CR-10 and Marlin 1.9. I hve printed some parts and all is ok. But suddenly, if i want to change the nozzle, i move the z-axis a long way upstairs, and now there is no way to get down. Every homing the z-axis goes a short way up, then x and y is homing, but z goes not down to the switch and stopps. I have dissabled the limits and want to move manually down, but that does not work, only up works.
What problem could be? I have reflashed the firmware with an ISP-Dongle but the same problem.
Can somebody give me a hint? The z-axis has a BL-Touch and the originally limit switch. Neither the switch nor the BL-Touch on z makes a difference. Sorry for my bad english....