How to change the mainboard (Sigma Series)

In this article you will learn how to replace the mainboard


allen key icon
Allen Key 2.5mm
screwdriver icon
Flat Head screwdriver


The mainboard is the part that controls the movement and temperature of the printer. It holds the firmware of the printer.

This article will show how to replace the mainboard in case the fuse was unable to protect it from external damage.


1. Turn off and disconnect the printer.

turn off sigma d25

unplug sigma d25


2. Remove the lower bowdens from the FRS.

bowdens and frs


3. Remove the bottom Z cable covers. Follow the next article to know the process: How to remove the Z cable cover.


4. To get access to the inner cover you will need to raise up the printer surface, if you can't turn on the printer, you will need to manually raise the printing platform by spinning the Z motor lead screw.

z motor lead screw

5. Remove the frontal inner cover. Follow this guide to know how to do it: How to remove the inner cover


6. Disconnect all the cables including all the flat cable connections and unscrew the 3 corners of the mainboard, be sure to keep the plastic loafers.

flat cable connection

8. Screw the new mainboard and reconnect all the flat cables.


9. Remember to check the flat cable connections before turn on the printer to prevent shortcircuits. Visit this article to get more information about this:

How to check flat cable connections (Sigma Series)



If replacing the mainboard doesn't fix your issue, please get in contact with the support team by filling this form: Support form.

Forum community 

Repair didn’t go as planned? Check out our forum community for troubleshooting help.


It's important to keep your printer in good shape to make the most out of it. In this chart, you can find a list of the extruder maintenance procedures and how frequently these should be done. Maintenance Plan


bcn3d-recycle  Take your e-waste to a certified recycler. Check how we do it in BCN3D.





Buy these parts

mainboard 3dmart Mainboard SKU 10909 



check mainboard fuse eng


check flat cable eng


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