Mini autolevel fails but manual looks good via M119?

I have a Lulzbot Mini (version 1), running Marlin I can’t get past autolevel for the life of me. Octoprint always reports the Mini fails with “Error: Probing failed”.

When this happened in the past, I would clean the print head with isopropyl alcohol on a paper towel and successfully try again, but now it won’t get past the probing.

The printer attempts to probe all 4 corners, and only after touching the last corner does it stop and return the error. It does not crash into the washers, so it looks like it’s making electrical contact. It does not attempt to wipe the printhead and start again; it touches the 4th washer, lifts up, then returns the error and Octoprint sends M112 to shut it down.

When the plate and hotends are homed, M119 returns that x, y, and z mins and maxes are open, as expected:

Send: M119
Recv: Reporting endstop status
Recv: x_min: open
Recv: x_max: open
Recv: y_min: open
Recv: y_max: open
Recv: z_min: open
Recv: z_max: open

If I manually touch the hotend (controlling it via Octoprint) to each washer, I then see z_min return “triggered”. This is what has me baffled, as manually, I can see the firmware returning expected results for probing.

I am not sure what else to look for or what my next steps would be. Does anyone have recommendations? Thanks in advance!

This may be my solution: Lulzbot Mini does not touch 3rd washer ->

The bed was out of alignment on the X axis. I followed that procedure, did a test run, and made it past probing. I’ll try an actual print and report back if the issue is resolved.

That did it! During the test print, the hotend did push too hard to make contact with the washers (which it did not do during the dry run during my second message), but a quick wipe of the hotend with a scotch brite pad fixed that, so no need for any z-axis changes.

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Glad you got it figured out. My biggest issue with my Mini is getting the nozzle clean enough to make good contact with the washers for every single print. Recently I printed a pla tool with a file like surface which I have found works best for me. It’s about 6" long by an inch wide and the rough surface on it does the job without removing any metal. I love my Mini apart from this aspect. I thought that bed leveling was super important butI have a CR-10 for bigger jobs which only has mesh leveling. I set it up once about 50 prints ago which took less that 10 minutes and that part works well although print quality and speed are not as good.