Selftest (MK2)

Updated 1 week ago ​by Tomáš Chvalina

The first thing you will have to do after assembling your printer is the Selftest. Within this routine, the most common errors regarding the built and electronics wiring are checked. Selftest is done directly through Wizard, simply press [yes] once it asks if you want to run it or you can manually start the Wizard from the LCD Menu - Calibration - Wizard.

This procedure should not be necessary for fully built printers.

Self-test consists of: 

  1. Extruder and print fan test
  2. Heatbed and hotend proper wiring
  3. XYZ motors proper wiring and functionality
  4. XYZ endstop mechanical settings and proper wiring axis length
  5. Loose belt pulley test

Progress and results of each step are displayed on the LCD. In case of any errors found, the self-test will be interrupted. You can check out all of the errors below.

Self-test error messages (MK2)

Extruder & Print fan test

Front print fan/ Left hotend fan - Not spinning:

  1. Make sure that both of your fans are connected properly to the MK2/MK2S Electronics Wiring.
  2. Check for any blockage that could prevent either of the fans to spin. 
  3. Go over the wiring and make sure that none of the zip-ties is over-tightened and preventing fans to spin.

Heatbed & Hotend test

Please check/ Not connected - Heater/ Thermistor: Bed/ Heater - Wiring error:

  1. Make sure that both thermistors and heater are connected properly to the MK2/MK2S Electronics Wiring.
  2. Check if your Heated bed cables are not damaged by overtightened zip-tie. 
  3. Investigate your Heated bed thermistor. It must be perfectly attached under the Golden Kapton tape.

XYZ endstop & motor test

Endstops - Wiring error - {XYZ}:
Motor - {XYZ} - Endstop {XYZ}: 

  1. Once you trigger this error, it means that either X/Y endstops or X/Y motors were not properly plugged in the miniRAMBo board. 
  2. So simply go to the MK2/MK2S Electronics Wiring and switch them to its proper position.
Be aware that once misplacing both at the same time, self-test will not be able to catch the error.
Please pay extra attention once re-doing the electronics wiring.

Loos belt pulley test

Loose pulley - {XY}:

  1. Simply make sure that both of your pulleys are properly tightened. If they would not be, then they would be spinning around the motor shaft without moving the axis.
  2. Make sure that your belt isn't extremely loose, as it might be just going around the pulley without actually moving either of the axis.

Would you still have any problems, please do not hesitate to contact us at

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