@grahamexp Weird, I removed the white and black wires from the plug on the bl touch end to check the crimps. Found no issue with the crimp. Then checked the plug on the duet end, again found no issue with the crimp. Put it all back together and switched on and now it works again. My testing the leads resistance didn't show any breaks or poor connections either. I am at a loss to explain this inconsistent behavior unless it is that internal pullup resistor.

@dc42 Thanks for the additional info. Ok so how do I disable the internal pullup resistor? I have checked the white wire for a loose connection, cant find one. Resistance across the wire lead is same as the other pins when I check with my meter (1.6 ohms for white, brown, orange and yellow).

@grahamexp is there a way to reset the BL touch and see if that doesn't fix this

@stephen6309 yea I think I am also going to follow that approach. ''BL touch and Rasberry Pi at the same time?'' was the help from yesterday.

@stephen6309 I removed the ! after the failed attempt already. Yesterday I had asked for help moving the one pin from the 26 pin connector. There was a suggestion that I simply unplug it as the second ground was not needed. I did this and it worked for the next Z homing. I suspect that the advice was not correct and may ne teh cause of my current problem. I have put the black wire back on pin 6 (ground) as it was in the hope that would correct the issue but it did not.

@grahamexp on the dashboard the Z probe status is highlighted pink and reads 1000 that was a 0 before when it was working correctly.

@grahamexp last time I had a similar problem the pin was bent, checked that also. Not the issue this time.

@grahamexp checked the wires all connected just fine. if i run probe deploy macro it works. retract macro works, self test works.

@stephen6309 yup that worked

@stephen6309 so now I have a disaster. tried the ! and instead of stopping the bed jammed up against the nozzle. Problem with moving it back is that it is a core xy setup using a worm wheel drive for the z axis so manually moving the bed down is not an option. On restart the entire homing function is jammed and I cant move Z until its homed