How to disassemble the LCD screen (BCN3D Sigma)

In this article you will learn how to remove the LCD screen safely


Fine spatula or Boxcutter
2mm Allen
Socket driver 5.5 mm


Firmware fixes may be released from time to time, and sometimes the LCD screen files need to be updated. Here's a link that will show you how to update the interface files. . How to update the files on the LCD


Either it's from this or just because the screen broke and needs replacement, you'll have to disassemble the screen of your Sigma.

In the Sigma there are two types of screen you may have, which have different assembly processes. Check them out and proceed according to the model you have:


R16 Version

R17/R19 Version


R16 Version

1. To disassemble the LCD screen turn off the Sigma and unplug the printer's power cable. 

sigma-turn-off-1 sigma-turn-off-2


2. Remove the central and the right side black covers. screw-iconx6 M3 8mm

screw-iconx2 sheet metal


Tip: You'll also have to remove the lower Bowden from the extruder motor, you'll need to unscrew it with a 1.5mm Allen Wrench.




This is the same removal procedure as the Sigma R17.

Go to the R17/R19 assembly


3. Loosen the two nuts that hold the LCD to the frame. You’ll need a 5.5mm socket driver. nut-iconx2 M3


sigma-1screen-4 sigma-1screen-3


Tip: These nuts are difficult to reach, you can use a flexible arm attachment for the socket wrench to make it easier. 


4. Loosen the four small nuts to remove the LCD. nut-iconx4 M3



5. To reassemble the new LCD to the printer, follow the previous steps in the opposite order.

Tip: Check that the polarity of the LCD cable is the correct one. There are two rows of pins to connect the LCD cable. The connector should be connected in the lower row with the white cable unplugged:


If you need to replace the screen with a new one, this version is discontinued, you'll have to install an R17/R19 screen. Make sure to update the interface files.


R17/R19 Version

1. Remove the central and the right side black covers. screw-iconx6 M3 8mm

screw-iconx2 sheet metal


If your printer is a Sigma R17, you'll have to remove the lower Bowden just as the Sigma R16.


If your printer is a Sigma R19, press the coupling collet, disconnect the filament sensor and pull down the lower Bowden:

_MG_2333 _MG_2332



2. Apply pressure on the rear of the LCD while detaching it with a fine spatula or a boxcutter. After applying pressure, you’ll get enough space to introduce the tool between the printer’s frame and the LCD.


Warning! Do NOT slide the tool in the left side. Just on the upper, lower and the right side areas


3. Disconnect the flat cable from the LCD.


4. Disconnect the flat cable from the adapter board.lcd-flat-cable-2

Notice: The flat cable has to be connected with the silver pins facing upwards at both ends.


5. Disconnect the multi-cable from the adapter board.lcd-flat-cable-3

Notice: The multi-cable connection orientation: The white cable should be out of the connector and the smooth face of the connector should be facing upwards. 


6. To reassemble the screen, follow the same steps in reverse order.



If you still experience issues with your screen functionality, it is likely that the interface files have to be updated. Here's how to do this: Update micro-SD files BCN3D Sigma


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

Forum community 

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


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


Parts   Buy these parts
lcd-component BCN3D Sigma/Sigmax Touchsceen SKU 11060


check flat cable eng


update lcd sigmax eng


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