How to Check and Change the Mainboard's Fuse (Epsilon Series)

In this Article you Will Learn how to Check and Replace the Mainboard's Fuse









Allen Key 2.5mm
Flat Head screwdriver


Our mainboards have a removable fuse (0451012.MRL) that protects the mainboard from shortcircuits. If your printer is not heating both hotends along with the bed, and the motors are not working, you will likely need to change the fuse. To check and change the fuse, follow the next steps:


1. Turn off and disconnect the printer.

bcn3d-epsilon-turn-off-1 bcn3d-epsilon-turn-off-2


2. Remove the extruder motors cover in the back of the printer by loosening the two thumbscrews.



3. Remove the lower bowdens from the FRS.



4. Remove the Z cable covers. Follow the article below to understand this process:

How to remove the Z cable cover.



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


6. Remove the inner cover. Proceed to the article below to understand this process:

How to remove the inner cover



7. The mainboard's fuse is located on the left side at the top of the mainboard. To remove it, pull out the fuse by levering with a flat head screwdriver. If the fuse is damaged, replace it. The fuse doesn't have polarity, you can install it in any direction. 


mainboard-fuse-bcn3d-2 mainboard-fuse-bcn3d-1


8. Remember to check the flat cable connections before turning on the printer to prevent shortcircuits. Visit this article for more information on this:

How to check flat cable connections (Epsilon Series)



If replacing the fuse doesn't fix your issue, please contact the support team by filling out 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.

Parts   Buy these parts
fuse-bcn3d Mainboad's fuse SKU 10222 



replace mainboard eng


check flat cable eng


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