How to replace the Hotend flat cable (Sigma Series)

The flat cables connected to the print heads are in constant movement and with time it is possible that they need replacement because of the wear damage.






Allen Key 2mm
Allen Key 2.5mm


warning-2 This is an advanced repair article. This guide is designed to be performed with the authorization and assistance of the BCN3D support team or authorized distributors.

Without the necessary knowledge, you could cause damage to the printer during repair and invalidate the warranty.

If you have any questions or problems please contact the support team: contact form.


If you have checked the cables and found that they are damaged, this article will help you replace them:

1. Raise the printing surface to the top (Utilities/Maintenance/Move printing Platform)

Move printing platform

2. Turn off and unplug the printer.

turn-off-d25 unplug-turn-off-d25

3. Remove the Z cable cover and the inner cover.

You can get more information about how to do it in the following articles:

How to remove the Z cable cover (Sigma Series)

How to remove the inner cover (Sigma Series)

sigma-d25-z-cover sigma-d25-inner-cover-2

4. Remove the connection cover and disconnect the flat cable from the extruder board.

screw-iconx2 M3 8mm


If the last 4 digits of your printer's serial number are higher than 0381, you should take the following into consideration:

  • Warning! The piezo cable is extremely sensitive, use caution when handling it.


5. Disconnect the flat cable from the mainboard.


6. Remove the ribbon cable from the printer and insert the new one by inserting it through the tacks.

flat cable clamps epsilon

  • Note: This cable should be positioned behind all other flat cables

7. Connect the ends of the flat cable to the extruder board and the mainboard.

8. Check the flat cable connections.

It is extremely important once the change is made, to check that all the flat cables are correctly connected, during the process they are very likely to come loose from their position. 


Parts   Buy these parts
flat cable Flat cable Left hotend - Sigma Series FFC H0 SKU 16514
flat cable Flat cable Right hotend - Sigma Series FFC H1 SKU 16516
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