3D touch will not auto home

Greetings,

My CR10 has been working nicely for years, but has suddenly developed a problem casing prints to stop. I traced this down to the auto homing. The X and Y axes home correctly, but the Z axis will not move down. The 3D Touch pin will deploy (extend) during homing but then seems to automatically retract. casing the print to stop. The LCD screen shows "Endstops Z" message.

When I test using the BL Touch menus. the self test, deploy and stop all seem to work fine? I have tried resetting settings and EEPROM .

My setup is Marlin 1.1.9, CR10 with Dual X Axis and v2 motherboard.

Has anyone experience of this issue. Suggestions appreciated.

regards
John

I reproduced the error whie connected to Repetier. Happens on Z homing. See attachment.

Any clues as to where I can find the actual error?

regards
John

Though I'd share the solution to save others time.

Basically, the issue was a bad connection on the black or white wires connected to the z-stop socket on the motherboard.

This time around I have plugged the original z end-stop cable back in the board and connected the black and white wires to where the z end stop used to be connected. I this allows me to revert back to a microswitch if the 3D Touch plays up again!

John