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Selftest Wizard - Z-Axis  

Active Member
Selftest Wizard - Z-Axis

I am a little confused on the selftest wizard in regards of the Z-axis check.

When I run the wizard, the green hook for the Z-axis is visible already when the selftest starts. The Z-Axis is not moving while any sequence of the test.

I saw the same behaviour in the YouTube video from Prusa "Original Prusa MINI - Calibration and First Print" (I don't link the video here, due to avoid the "awaiting moderation" delay - I hope)

Does anyone of you have the same behaviour?


I wouldn't care if everything would work properly afterwards, but it doesn't.

No matter where the Hotend-Unit currently is on the Z-Axis, the printer consider this as the "0" Position. So if it is some where in the middle, I won't go further down. Move Z-Axis in the setting menu can lift it up, but not further down. Mesh bed leveling is not possible.

I can do prints, but only when I switch off the printer and move the Z-Axis manually down, until the nozzle tips the heatbed.


Support is already involved, and they assume a broken MINDA cable, but I doubt a little that this is the (only) issue here.

Mesh bed leveling works, and there is no LED flickering on the MINDA while the leveling. The only thing I noticed is that the LED on the MINDA dims down until it switched off (which is as I assume, the signal that distance point is reached).

Does your MINDA dims down, too? Or is it only light on / off?


Side note: This is already the third MINDA. First one definitely had a broken cable, second one worked until some new issues came up (Mesh bed leveling moved the Z-Axis up, but no down), and the third one (currently installed) works for PLA prints, but have (next to the issues mentioned above) first layer calibration issues when printing with PET-G / ABS -> higher bed temperatures. Every first layer comes out differently; too high, too low by same Z-adjustment values. (same behaviour had MINDA one, after repaired the MINDA cable provisionally).

Posted : 25/01/2020 11:55 am
Gabriel S
Trusted Member
RE: Selftest Wizard - Z-Axis

My MINDA dims down until it goes out as it approaches a surface.

Posted : 27/01/2020 2:36 am
Active Member
Topic starter answered:
RE: Selftest Wizard - Z-Axis

Hi Folks,


short update on this topic:


First off all, thanks to @g-j-sieben for your feedback. So dimming MINDA LED seems to be usual behavior; all of the MINDAs ever mounted on our MINI did/do this (currently we are on No.4).


Also, the green hook for the Z-axis is visible already when the selftest starts, seems to be usual. I found several videos on YouTube, where the selftest wizard is shown, and all of them showed this behavior. Curious, but no need to worry about.


Regards to the “0” position of the Z-Axis after selftest wizard: My current assumption is, that there is a bug in the wizard. After performance test of all components, it should do the "Auto Home" as part of the wizard, but it doesn't.

When I run the "Auto Home" as single test after the selftest wizard, the printer find an appropriate "0" position.

This will be hopefully solved within the next Firmware release.

Posted : 03/02/2020 11:52 am
burtronix liked