Troubleshooting a problem with your Smoothieboard

If you have a problem with your Smoothieboard, don't panic.

First of all, make sure you have read the documentation on this website, it is likely the information you are looking for is here, it is a very complete documentation. In particular take a look at:

If you can't find your answer here, you can also ask for help in the community. There are many channels:

Before doing anything else

Including asking for help, please read the “How to troubleshoot” section bellow.

And of course try to find the answer to your question on this page too.

Below is the list of the most common problems and things you can try to solve them :

Here are some of the things you should do when running into trouble, and before asking any kind of help around :

1. Backup your configuration file

Take your SD card out, and save your configuration file to your computer. If you are going to be messing around with the printer, you'd better be safe and make sure if anything happens to your SD card, you will not loose the work you put into your configuration file.

You should really have done this already, it's just good sense.

2. Clean your SD card

Sometimes SD cards get corrupted, and it can cause all sorts of weird and difficult to understand problems.

You should :

  • Format your SD card ( as FAT32 )
  • Paste the most recent firmware file on your SD card
  • Paste your configuration file to the SD card
  • Insert the SD card back into the board and reset it

Then see if your problem still exists or not.

It's probably a good idea to do this even if you don't think it's a SD card related problem, quite often people think it's not and it fixes the issue anyway.

3. Incremental wiring

This may not apply to your specific problem, but if it does :

Unplug everything from your board, then plug things back into the board one at a time, resetting the board and testing your problem each time you do.

Start with USB, then the power supply, then do the same for each peripheral in turn until everything is plugged back in. If you do not know what the problem is, it should help you pinpoint it.

4. Prepare your config for asking for help.

Open your configuration file.

Copy it's content.

Now go on the website.

Paste your configuration file's content into the « New paste » box

Click on « Create new paste »

The website will give you a link. You can now give this link to people on IRC or the forums, without having to copy/paste the entire file, and people will be able to see your config and help you.

5. Before asking the community for help.

If you have an Open-Source board like the Smoothieboard, a board from Panucatt, or one of the many designed by the community and that support the project, ignore this.

If you chose to buy a closed-source derivative board, however, please understand that those are considered to be toxic to the project, and that asking the community for help with those would be similar to asking the community to help with destroying itself.

Please ask for help from the person that sold you that board, before asking the community for help. Providing support for their product is the absolute very least they can do. And of course unsurprisingly they are well known for not doing even that. But please ask them first.

If they don't help you, then feel free to ask the community, but please be aware even then some won't accept to help. If this happens please remember that the community helping you is a service they are giving you, and that when they choose not to, they are only not doing you a favor.

Smoothieboard does not work at all

First off, do any LEDs turn on on the board when plugged in via USB ?

If not, that's very bad, contact your seller.

If LEDs turn on, it then depends on what they do :

There is a series of LEDs on your board, near the center.

They are labelled VBB ( red ), 3.3V ( orange ), and 1 2 3 and 4 ( all green ).

We are still only interrested in the green LEDs.

Different behavior can represent different situations and problems for the board :

Normal pattern

If your LEDs do this :


Then the firmware is running, and the LEDs are displaying correct behavior.

SD card problem

If your LEDs do this :


Then the firmware is running, but the board encountered a problem reading or accessing the SD card, or the configuration file on the SD card.

Try taking the card in and out of the board several times, or try using another SD card ( here is how to set up a new card ).

See bellow for more details.

Firmware crash

If your LEDs do this :


Or this :


Then the firmware is not running. You can try flashing the firmware again.

See bellow for more details.

Plugged in and 3.3V LED is OFF

This means the microcontroller on your Smoothieboard is not getting any power.

Smoothieboard gets this power from your USB cable (unless you are using the optional voltage regulator or the 5V input): check that Smoothieboard is correctly connected to a USB port or otherwise powered.

If it is, but the 3.3V LED is still not lit up, one other possible reason would be a short on your board.

Unplug the USB cable, and disconnect everything else from your Smoothieboard. Then plug the USB cable back in and check if it starts working again.

If so, there is a short in one of the peripherals. Quite often this is due to incorrectly wired Endstops (shorting 3.3V to GND instead of connecting GND to Signal for example).

If this still does not solve the problem, examine the board for problems with your soldering of components/connectors and any other anomalies you can detect.

If you can still not find anything, contact the community.

The 3.3V LED is ON but LED4 is not ON

LED4 indicates SD card status. If it is not lit up, it means there is a problem with your SD card.

First thing to try is taking the microSD card out of your Smoothieboard and testing it on your computer with a SD card reader.

If it works there, copy the files that are on it elsewhere, format it (as FAT32), copy the files back on it and try again.

If it still does not work in the Smoothieboard after this, take another microSD card, format it (as FAT32), copy the files to it, then try again.

If it still fails, then as you tried two SD cards they are probably both fine. The problem could be with the files on it.

Format a SD card as FAT32, and on that fresh card, copy two files: 

  • firmware.bin , with this exact name, which you can find here
  • config , with this exact name, which you can find here

Then insert the card into your Smoothieboard and try again.

The 3.3V LED is ON but none of the 1 through 4 LEDS is ON

Or LED1 and LED4 are ON, but LED2 and LED3 are not blinking.

This could be caused by a firmware bug, or by a problem with your configuration file.

Try with a fresh configuration file, and if it does not solve the problem contact the community.

If you soldered the smoothieboard then check either the 12 MHz oscillator or the SD card/SD card slot.

  • This could be a bad solder joint with the 12 MHz oscillator (crystal), a bad SD card slot, a bad SD card, and/or a bad config file.

12 or 24V power is plugged in but the VBB LED is not ON

Unplug power immediately !

Check that your power is not in reverse polarity.

Even if you think you have it correct (read the instructions carefully, the markings on the board can be a bit confusing), try reversing it just in case.

All LEDs are on but LED 2 and 3 are solid

Firmware didn't get flashed, you need to flash it and also make sure you uploaded a valid config.

It smells like something is burning!

Whaaaaa! Unplug everything! Get a fire extinguisher!

Now, try to remember exactly what you were doing with your board, and contact whomever sold it to you.

Mosfets are never turning on

You configured everything right and plugged the heating elements into your mosfet outputs, but no matter what you do, they do not turn on.

Note Smoothieboard does not have a single power input. It has one for the motors, and then the big mosfets have their own inputs, and the small ones have theirs. You need to provide power to each, according to the mosfets you are using. See the documentation on this, it goes into great detail and has diagrams.

Changes to configuration are ignored in general

The config changes are not taken into account, files do not appear or do not update on the SD card

If anything like this happens, that could be related to the SD card “messing up”, format the SD card ( as VFAT/FAT32 ), then paste your files back on it.

See SD card.

Sometimes the SD card can get corrupted after which it will do strange things. Always make sure you unmount ( virtually not physically ) your SD card after doing anything on it

Changes to configuration are ignored on a particular line

If a line begins with the # character, it means it is “commented out” and Smoothieboard will ignore it.

You need to remove the # character and Smoothie will now take the line into account.

My stepper motor does not turn correctly

If it always turns in the same direction, and/or turns only weakly, and/or makes a strange sound, one very common cause of that is that only 3 of the wires of the motor are connected to the stepper motor driver.

Check your connector and your cables.

If that doesn't help, do the following : 

  • Try this motor on another stepper motor driver
  • Try another motor on this stepper motor driver

My stepper motor does not turn at all and makes a very high-pitched sound

This can happen with Z axis (or any leadscrew driven stepper motor) due to the high steps per millimeter number. You are probably trying to move it too fast. Try asking it to move at a much lower speed ( for example G1 Z100 F100 ).

If you are using external stepper motor drivers (driven by ENn, Stn and DIRn pins) check polarity, voltage and timings of signals to your driver. Also consider increasing microseconds_per_step_pulse slightly if the default 1us pulse width is too narrow for your driver or cable lengths.

My stepper motor does not turn at all

And it does not present any resistance/torque when turning it manually :

This means the stepper motor driver is maybe not able to power the stepper motor.

Try wiring a different motor to that driver and try again. If the new motor works on this driver, then the motor is the problem. Otherwise the driver is probably the problem.

If you changed any of the stepper motor driver pins in your configuration, try testing again with a fresh configuration file.

My stepper motor turns in the wrong direction

There are two solutions to this :

You can reverse the order of the wires on the stepper motor connector.

Or you can edit your configuration file. For example, if you have this problem on the beta stepper motor driver, you need to invert the direction pin for that driver : 

beta_dir_pin                                 0.11

Becomes :

beta_dir_pin                                 0.11!

Save, reset and start again.

My stepper motor loses steps

Losing steps means not moving the exact number you asked of your motor. This will result in your machine losing its position and working where it shouldn't, often in the form of small offsets.

There can be several causes to this, here are some things to try: 

  • Make sure you have correctly set the current value for that stepper motor. Too high as well as too low values can cause this problem
  • Make sure there is no mechanical problem in your machine, like misaligned axes, things hitting other things, too much tension in belts, things like that
  • Is your stepper motor driver too hot to touch? Try aiming a big fan at your board (ideally the bottom of it), the stepper motor drivers might be overheating and shutting down for safety reasons. Never put heatsinks on top of your drivers, they are designed to be cooled from the bottom.

Homing does not work

You ask Smoothieboard to home an axis, and instead of going to the endstop and stopping there, it either does not move at all, or moves a little bit and stops.

What is probably happening here is either Smoothie thinks your endstops are always triggered (even when they are not), or it things they are triggered when they are not and not triggered when they are (inversion).

If it thinks they are always triggered, check your wiring.

If they are inverted, there is either something wrong with your wiring, or your configuration. See the Endstops section for more information on how to fix this

Homing does not stop when hitting the endstops

The endstops are always read as not triggered. Check your wiring and see the Endstops section for more information on how to fix this. Also sometimes having the sdcard mounted on the host (especially Macs) will cause this, unmount the sdcard and see if it still happens.

I can not connect to my board on Windows

Depending on the version of Windows, you might need to install the Windows Drivers for Smoothieboard

Note on Windows10 the drivers are not needed, and installing them can cause problems.

I get disconnected from my host frequently

This can be caused by several things :

  • Make sure you use a short good quality shielded USB cable with ferrite beads on it.
  • Make sure the Smoothie PSU is plugged into the same outlet as the PC you are connected to, otherwise you can get ground loops.
  • If your printer is unusually large, add ferrite to everything coming from or going to your board ( motors, endstops, thermistors, mosfets, etc )
  • Try using a shorter USB cable
  • Make sure your power supply is clean ( ideally with an oscilloscope )
  • Route wires for motors and mosfets away from signal cables ( endstop, thermistors, USB, etc )

See the USB page

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Smoothieboard Mass storage (SD card) is recognized, but not the Serial interface, on Windows

Please take a look at windows-drivers and see next section if that does not work.

How to disable MSD permanently

Install this version or firmware (Remember to rename it firmware.bin)

and add this to your config file

msd_disable  true  # disable msd

The mass storage device will no longer be available, but serial should work.

Smoothieboard Mass storage (SD card) won't mount on my host computer

Even if the smoothieboard seems to work OK, this is almost certainly a problem with the SD card itself. Try using a different SD card. This problem has been reported with some SD cards that shipped with the original kickstarter boards. See this thread for more discussion of the problem. See the SD Card page for information about setting up a new SD card.

Motor won't turn but all lights are correct, motors make no noise at all

Bad USB cable or insufficient power to 5v(Required to give motors enable signal) - Don't underestimate the power of a bad USB cable to waste hours or days of your life.

Pronterface ignores my commands

If sending a command to the board via pronterface and it is being ignored, that is because you need to “escape” it by adding @ before it.

For example do not send version but send @version.

My machine was executing a file and it stopped

First thing to check : open the Gcode file and verify it's not truncated. This can happen for example due to errors copying the file. It's more common than you would expect.

Second thing, check the Smoothieboard is not in “Alarm” mode. If in Alarm mode, it should turn off it's heaters, but refuse to move. Sending the M999 command puts it back into normal mode, but first check your host program for the message Smoothie sent telling it what the problem was, most problems that cause it to go into alarm mode are problems that deserve your attention. It can be hitting a limit switch, or a problem with temperature control for example.

I'm very upset at something, everyone is mean and nobody listens to me

Now this isn't meant to offend, and it probably doesn't apply to you, but keep reading.

Smoothieware is an Open-Source firmware developed by volunteers on their free time. They are giving it to you for free. It's a favor they are doing you. They are being really really nice to you.

The people in the community who help you, do it in their free time, and could be drinking beers with their friends instead of helping you.

Before you get offended at: 

  • People not answering you fast enough
  • People asking you to read the documentation
  • People not willing to help you right now
  • People not implementing something you want
  • People not not taking your recommendations into account
  • Etc

Please please please remember you are talking to volunteers. You did not pay for the firmware, it's free, and it was done by people who did it to make the world better, with their own free time, and sometimes their own money. All for you, without even knowing who you are.

If you have a problem with your Smoothieboard, the hardware itself, you did pay for that, and you are entitled to your issues being resolved. Contact the seller and they are legally obligated to help you, and they will gladly do so.

But the people in the community are not obligated to do anything, you are not entitled to their help or attention. They are doing you a favor, and if they choose for whatever reason not to do you a favor at any given time, that is not depriving you of anything, that is just « not volunteering to do you a favor ».

To be clear, the Smoothie project is mainly composed of two parts :

  • The Smoothieboard hardware, which you paid for, and are entitled to help/fixes for only from the person who sold it to you, not the community, contributors, or anyone else
  • The Smoothie firmware, which is free, you didn't pay for it, and no-one is obligated to help you with. It so happens that the main Smoothieboard sellers have a policy of helping users with firmware problems even though they are not obligated to ( again : you didn't pay for the firmware, it is free ). But the community and contributors are definitely not obligated to help you with it in any way.

If somebody in the community is not willing to do what you want, remember you didn't pay them, and contact your seller instead.

This is a nice read on the subject:

Again: this probably doesn't apply to you, but if you are upset, please take a moment to consider if maybe this applies. If you are upset and it doesn't, please contact your Smoothieboard seller as soon as possible, the main reason for frustration is users waiting too long to contact their sellers for help.

Very important: if you are upset because your board burned, your seller did something wrong ( please contact them, they really don't want you to be upset ), or anything like that, this does not apply at all. This is only about interacting with the volunteers in the community.

I asked for help for the 15th time today and nobody wants to help me anymore

My board works, now what software do I use with it?

Try one of these:

All software below either knows how to interface with, or how to generate g-code for, Smoothieware.

3D Printing


  • bCNC - Open-Source CNC host with great preview and other operations. Set machine type to smoothie. and add grbl_mode true to your smoothie config (Note: You must update to the latest version of Smoothieware to ensure compatibility with bCNC).
  • - Open-Source Simulation & Computer Aided Machining (Free 3-axis CNC Simulator which understands G-Code)
  • CNC.js - Open-Source CNC host with lots of features, running in your browser.
  • - Open-Source CAD software.
  • GCode plug-in for InkScape - CAM, Output GCode from SVG files in Inkscape.
  • PyCAM - Open-Source CAM software.
  • jscut - Open-Source in-browser CAM software.
  • CamBam - Closed-Source, but cheap and feature-full CAM software. Widely used by hobbyists.
  • Fusion360 - Closed-source CAM with very advanced features, free for hobby/fablab/small business.
  • Fabrica - Easy to use web control interface ( Host )



  • This plugin for Fusion360 allows you to start your Gcode files from within Fusion360 directly using Universal Gcode Sender ( skipping the step of first saving the file in Fusion360, then opening it in Universal Gcode Sender )


A few words you will see in this documentation that require a bit of explanation :
  • «Host» software is software that is used to “talk” to your Smoothieboard. It allows you to control the machine ( for example “jog” the axes ), to “stream” a G-code job, or to upload it to the SD card, things like that.
  • «Slicing» software is software that is used to take a 3D model file, and based on some settings you input, “slice” it into layers, and generate a G-code file that the Smoothieboard can then execute to print a thing.
  • «CAM» software, or «CAM Package», for Computer Assisted Manufacturing, is software that is used to take a 3D or 3D file, and based on some settings you input, transform it into a list of tool movements ( G-code file ) for a machine that uses a tool to remove material from a workpiece.
2017/01/25 14:20 · arthur