How to solve SD card reader issues (BCN3D Sigmax)


Allen Key 2.5mm
Socket brench 3mm 
Phillips screwdriver


If you spot that the information of the file that you will print is not correct, it's bugged or the system asks you to insert an SD card even though you have one plugged in, you are experiencing SD reading issues. It is also possible that during the printjob, the screen shows illogical values or the printer moves in a strange way. Follow this troubleshooting guide to locate the issue:



SD card verification


1. First, make sure that the SD card is properly placed, and that it is unlocked.


2. If you have another SD card, try it as well, to make sure that the issue isn’t being caused by a defective SD card.


SD card reader change


1. Move the printing surface up to have access to the printer’s central cover. Then turn off and disconnect the printer.

sigmax-turn-off-1 sigmax-turn-off-2


Note: To move the printing surface, go to the menu Move printing surface: 

Options/Maintenance/Move printing surface


2. Remove the central and right side covers using the Allen key and the Philips screwdriver.

screw-iconx6 M3 8mm  

screw-iconx2 M3.2 9.5mm

sigmax-inner-cover-1 sigmax-inner-cover-2


3. Disconnect the SD reader cable, paying attention to the position of the cables.



4. Remove the two nuts which hold the SD reader to the frame of the printer. nut-iconx2 M3




5. Once the SD reader is removed, loosen the screws which hold the SD reader to the metal support. screw-iconx3 M3 8mm


Place the new SD reader and install it in the printer.


Front Back
sd-card-reader-6 sd-card-reader-7



Usually, the reading problems are caused by the SD card and in fewer cases by the SD card reader. If you are using a micro SD card adapter, check if it is okay and try to change it before changing the SD reader.

Is important that the SD card is formatted in FAT32 to ensure the correct reading process. 

Forum Community


This article doesn't fix your issue? Check out our forum community for more info about this


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
sd-reader-component SD reader SKU 10973


update lcd sigmax eng

check mainboard fuse eng


You can help improve the BCN3D Knowledge Base.

If you feel there are guides that we are missing or you found any error, please use this form to report it. Report form :)