When you first turn on your Original Prusa MK4 printer, it will start a selftest to verify the most common components of the printer.
The printer goes through the following procedures:
The Loadcell test, Gearbox alignment, and Filament sensor test need user input, so stay near the printer for these parts of the selftest.
After the selftest, you can check the results at any time in the printer menu in Control -> Diagnostics -> Show Selftest Result.
In case one of the fans fails the selftest, verify if there is nothing blocking the rotation of the fans, as debris might get between the blades. Bigger parts can be cleared with tweezers, and dust can be cleared with a computer cleaner spray.
Hold the fan with your hand while using the compressed air. Otherwise, you might damage the blades.
During the Loadcell test, you will be asked to tap the nozzle at a specific time. In case you do not tap the nozzle, the printer will restart the loadcell test.
If the Loadcell is being triggered too soon, make sure that you are not touching any other part of the extruder other than the nozzle.
This test can be skipped, but skipping it can cause the nozzle to damage your steel sheet and heatbed.
In the case of a failure in the X or Y axis, check the following:
|Correct X-axis pulley orientation and position.||Correct X-axis pulley orientation and position.|
|Correct Y-axis pulley orientation and position.||Correct Y-axis pulley orientation and position.|
|The fan door screw must be tightened fully|
The Z-axis check will not be made if the Loadcell test is skipped.
In case the Z-axis test does not pass, check the direction of the trapezoid nut. Make sure that the hotend is properly positioned in the Nextruder.
After the filament sensor test, the selftest will heat up the nozzle and the heatbed to test them. The steel sheet needs to be on the heatbed for this test.
In case you get any errors, scan the QR code shown on the screen, or check our Knowledgebase.
In case you have a Prusa Nextruder Silicone, go in the printer menu to Settings -> Hardware -> Nextruder silicon sock, and toggle it ON.
If the filament sensor does not detect the filament during the selftest, you can check the LoveBoard to see if the cable is properly connected. Also, make sure that there is no debris in the Prusa ball holder.
It is possible to skip this part of the selftest, but in this case, the features that depend on the filament sensor might not work.