I have recently bought a D840 and have the following problem on the machine;
The first time a ran a job everything was working fine. When I send a second job, the machine started and after a few minutes uccnc gave a message saying limit switch reached. No hardware limit was hit and after resetting the machine, the limit is still active. Looking in de diagnostic page I see that alle limit switch status is on green. But the strange part is that also port 10, the eprobe is lit green.
After enabling limit override and moving the machine I see that sometimes the eprobe (port 10) is turing off and everything is ok and all limit status is cleared. But moving the machine some more the port 10 is lit again.
I have removed all the cables from the mainboard and just added some loops as I thought this might be some bad wiring. But even the port 10 is green and uccnc is stating a limit is reached.
I have then uninstalled uccnc and deleted the uccnc folder en reinstalled everything with the multiinstaller. Still I have the same problem. Also if I remove the red jumper and restart everything, the error is still there.