Editing 3D Printers (section)

=== Positioning System ===
There a few a different positioning systems commonly used on 3D printers. This includes Cartesian (XYZ), Delta, and CoreXY. Each of them has their positives and negatives, but outside of this, debugging them is fairly straightforward. If you think you have an issue with the positioning or extrusion motors, you can test this easily by feeding the printer the G code for the axis you believe is faulty. You can find this information easily by reading the reference for your firmware. [https://marlinfw.org/meta/gcode/ For example, here is the gcode reference for printers running Marlin]. Just direct one of the axes to move back and forth and see if it works. This also works for the extruder as long as there is no filament loaded. 

{| class="wikitable"
|+
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! Problem !! Solutions
|-
| Motors not driving at all || 
* Change the channel of the stepper; i.e. plug X into Y, or any other known working channel. This should tell you if it's the motor or the driver chip.

* Do you hear a stalling or whining sound? It's likely the driver chip is busted. Check windings on stepper to make sure no damage. 
* If other motors work in that channel but the specific one doesn't, the stepper may be dead. Check for continuity on the windings; it should be two sets of windings, so there should be two pairs of pins that are connected. If they measure open loop or one of the windings is bad, the whole motor will not work. Replace.
|-
| Motors only go in one direction  || 
* Driver chip failure. Replace.
|-
| Gets stuck driving one axis during initialization or finishes initializing immediately without moving || 
* Check that your limit switches work and are hooked up to the correct place.

* Use continuity mode to verify that the switch reads open while not closed, and then less than a few ohms when closed. 
* If you recently updated the firmware, make sure that the firmware has the polarity of the limit switches set correctly (switch polarity can be set in here)
|-
|Printer does not recognize the SD card
|
* SD card is damaged. Replace.
* SD card is improperly formatted. Compare with the user manual or the filesystem of the OEM card included with the machine, if available.
* Debris in SD card slot. Especially common in industrial settings. Clean slot with compressed air and try again.
* SD card slot damaged. Inspect and resolder if necessary.
* SD card may be locked, Check the lock switch on the side of SD card, and position the switch to the upwards position.
|-
|New printer turns on but is not recognized by the computer when connected via USB. Stepper motors stuck, hot, and buzzing.
The user interface does not respond. No physical damage found.
|
* Firmware corrupted from the factory. Flash the appropriate firmware for your model.
|}