Ender 3 V2 - Z axis only moves up

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1

Hello,

I have an Ender 3 V2 which has been reliable. I printed 3 items out over the last 6 days and auto homed the printer each time without issues. I tried to auto home after the most recent print job finished and noticed that the print head was not at its usual height.

Troubleshooting

  • Disabled the steppers to make sure the Z axis moves freely.
  • Power OFF, un-plug and plug-in the Z axis stepper, power ON again, the try auto home
    Result: Same issue, not auto homing correctly
  • Under Prepare → Move : Move Z axis Up (increase number)
    Result: Moves Up
  • Under Prepare → Move : Move Z axis Down (decrease number)
    Result: No Movement

In this state the Z axis does not move freely, I still need to disable the steppers to achieve this.

Do you have any suggestions or is the Z axis stepper faulty?

Thanks,
Brett

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2

Ok, this is bizarre. I have 2 extra things to point out.

I have OctoPi and a BLtouch.

OctoPrint reported " STOP called because of BLTouch error - restart with M999". Found the following at STOP called because of BLTouch error - restart with M999 · Issue #8926 · MarlinFirmware/Marlin · GitHub

  1. Blue LED will be ON if a servo signal is present. Blue LED is faint.
    Result: Blue LED is on
  2. M119 ; should return OPEN. If not check that the BLTouch is enabled in the configuration. If enabled then check wiring and check that the correct pin is being used.
    Result: Open
  3. M280 P0 S10 ; should deploy the probe and the orange LED will be OFF.
    Result: probe acted as it should
  4. M119 ; should return OPEN
    Result: Open
  5. M280 P0 S90 ; should stow the probe and the orange LED will be ON
    Result: probe acted as it should
  6. M280 P0 S60 ; puts it into the M119 test mode.
  7. The probe should remain stowed and the blue LED should be OFF.
    Result: probe acted as it should
  8. M119 ; should return TRIGGERED
    Result: probe acted as it should
  9. M280 P0 S160 ; returns it to normal operation
  10. M119 ; should return OPEN.
    Result: Triggered

I got exactly the same result. Afterwards, I used OctoPrint to move the Z axis Up 10 and Down 10. This worked fine. Can now auto home and bed level. I’m guessing that this is related to the BLtouch. A power cycle made no difference. Me: scratch head.

I hope this helps someone else. Sorry for the concern.

Thanks,
Brett

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3

Hi Brett,

Thank you for posting your answer - this will hopefully help out anyone with your issue in future.

Glad to hear your issue is confined to the BLTouch, though unfortunately that might mean you need a new one? If you find yourself making hardware changes to your printer frequently, I love Klipper, as you just edit a config file rather than rebuilding and flashing marlin each time.

I hope future prints give you less trouble :slight_smile:

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