BLTouch: No trigger on probe after full movement

General Discussion
1

Basic Information:

Printer Model: Ender 3 Pro
MCU / Printerboard: BTT SKR Mini E3 V2.0 (stm32f103xe, v0.11.0-41g9b60daf6), Klipper on Raspberry Pi 4 4GB (armv7l, v0.11.0-41g9b60daf6)
klippy.log will generate M112-log asap, log of last failed print-attempt is attached.
klippy_failed-print.log (96.7 KB)

Describe your issue:

I had some really rare cases of my BLTouch (3.1, original) trigger not being detected by my Klipper host. So I went to try some different settings.

  • probe_with_touch_mode: True always set to True
  • stow_on_each_sample:
    – True consistently leads to No trigger on probe after full movement on the fourth screw of SCREWS_TILT_CALCULATE, or in rare cases at some point in BED_MESH_CALIBRATE Now it suddenly works for testing, testing in print-condition soon.
    – False will work 99.9% of the time Tested some more, now it does not.

The issues with stow_on_each_sample are pretty consistent. I did change the USB-cable before making the change, but since it works pretty flawlessly with stowing, I do not think that the cable is the issue.
By setting position_min: 0 on Z, I was able to avoid the nozzle being dug into the bed each time, but I would like to get to the bottom of the issue (and ideally not stow the probe after each point).

2

Issue finally surfaced again, here is the log:
klippy(1).log (119.5 KB)

3

I am still running into this issue multiple times a day. I verified that the wired connection is securely attached, even put some hot glue onto the connectors to avoid any rattle. There is no consistency as to where the probe will fail, suggesting that it is not a broken cable.
The Bltouch is connected to the endstop-pins on the mainboard. If anyone has some input as to what I can try or check, I would be very thankful.

4

Apart from a defect BLTouch, you could try different pins, e.g. the dedicated probe port on the board.