Selftest (MK3)

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.

Selftest consists of: 

  1. Extruder and print fan test
  2. Heatbed and hotend proper wiring
  3. XYZ motors proper wiring and functionality
  4. XY axis length
  5. XY belts tension
  6. Loose belt pulley test 

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

Selftest error messages (MK3)

Extruder & Print fan test

Front print fan/Left hotend fan - Not spinning:

MK3 Selftest is capable of telling you which of the fans is not working. So, simply check the one that is diagnosed as not OK.

  1. Make sure that both of your fans are connected properly to the EINSY miniRAMBo board.
  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 EINSY miniRAMBo board.
  2. Check if your heated bed cables are not damaged by overtightened zip-tie. 
  3. Investigate, if your heated bed thermistor is perfectly attached underneath the Golden Kapton tape.


XY axis length test

Please check: Axis length - Axis {XYZ}: 

  1. Start the Selftest routine again in the LCD Menu - Calibration - Selftest. Closely observe if there is not anything blocking the path on any of the axis.
  2. Pay attention to your extruder cable management and assembly of your axis. The most common source of the improper X axis movement is the cable stuck hitting the EINSY Mini RAMBo cover.

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 neither of the axis.

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

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