Problems can show up in all shapes and forms in 3D printing, whether it’s an obvious one that displays an error message on your computer’s or your 3D printer’s screen or one that harms the 3D printing process silently, without any warning to tell you that something has gone wrong.
Between the two, we can comfortably say that facing an error message is always better than the 3D printer malfunctioning in a silent manner, as an error message will most likely prevent the 3D printing process from moving forward, whereas a quiet problem is capable of creating disastrous results.
In today’s article, we will be diving into one of the errors that come with a message, which you can encounter on your 3D printer if it’s running the Marlin Firmware, where the text “SD init fail” shows up on the screen, practically telling us that something has gone wrong with the initialization of the SD card.
So, what can cause the SD init fail error in Marlin Firmware?
Below are the most common culprits that can cause the SD init fail error in Marlin firmware:
- No SD card in the slot
- Improperly formatted SD card
- Defective or malfunctioning SD card
- SD card capacity too high
- Misconfigured firmware
- Buggy or corrupted firmware
- Malfunctioning mainboard
Next up, we will be examining the cause behind the SD init fail error in Marlin Firmware with better detail, find out what we can do to fix the problem and get rid of the error, and finally, take a quick look at the specific case of encountering this error on an Ender 3.
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What Causes the SD Init Fail Error in Marlin Firmware?
While the SD init fail error isn’t a critical one that you should be concerned about, it is an error that will disrupt the printing process as it essentially means that the 3D printer is not able to communicate with the SD card.
- There is no SD card in the SD card slot. The absence of a SD card in the SD card slot is the very first thing that can trigger the SD init fail error, as there is nothing to initialize if there is no SD card.
- The SD card is improperly formatted. As the firmware won’t be able to read the SD card unless it’s using the MBR partition table and the FAT32 filesystem, a card that is formatted without these specifications will end up with the SD init fail error.
- The SD card is defective or malfunctioning. A defective or malfunctioning SD card can prevent the 3D printer from communicating with the SD card, essentially creating a scenario where the SD card doesn’t exist for the 3D printer.
- The SD card capacity is way too high. While there is no official information on this, SD cards with over 8 GB can prevent your 3D from reading them at times due to unknown reasons, which can prompt the SD init fail error.
- The firmware is misconfigured. If you have upgraded to an LCD controller with an SD card slot, the slot won’t operate unless you perform the necessary configuration, causing the 3D printer only to detect the empty onboard SD card slot. In such a case, the SD init fail error will pop up due to the lack of an SD card.
- The firmware is corrupted or buggy. In some cases, it’s possible for the firmware to be corrupted during flashing or to have buggy code that causes problems, which can be the culprit behind the SD init fail error.
- The mainboard is malfunctioning. A malfunctioning mainboard with an SD card controller that isn’t working as intended will prevent the firmware from being able to communicate with the SD card, which will cause the SD init fail error.
How to Fix the SD Init Fail Error in Marlin Firmware?
Fortunately, fixing the SD init fail error should be a straightforward process in most cases since there is no mystery surrounding the culprit behind it, and not a lot of need for technical expertise to perform the necessary operations to get things working.
- Ensure that there is an SD card in the SD card slot. Even if you don’t need an SD card for the printing process, inserting an SD card into the slot is the first step we recommend, as it’s highly likely to resolve the problem.
- Reformat the SD card with the correct partition table and filesystem. While the formatting process varies based on the operating system you’re using; you can use diskpart on Windows to convert the partition table to MBR and format the partition as FAT32.
- Clean the contacts on the SD card. For this process, we recommend getting some IPA on a Q-tip and slowly cleaning each contact pin gently and thoroughly.
- Re-flash an up-to-date and correctly configured version of the official Marlin firmware. Uncomment (remove the double slashes at the start) the SDCARD_CONNECTION parameter in the Configuration_adv.h file. Use the LCD parameter for the SD card slot on the LCD controller and the ONBOARD parameter for the SD card slot on the mainboard.
- Replace the SD card with a new and lower-capacity one. We recommend purchasing an SD card below 8GB, which will ensure that you don’t face any problems related to the capacity.
- Replace the mainboard of your 3D printer. If all else fails, replacing the mainboard can be the only solution unless you have the technical knowledge to replace the SD card controller and see if that helps.
SD Init Fail Error on the Ender 3 (Pro/V2) Screen – What to Do?
Most of the reports in the community about the SD init fail error come from Ender 3 users, which is no surprise considering that the Ender 3 is the most popular 3D printer on the market right now, and most Ender 3’s run on Marlin firmware.
As the Ender 3 runs a modified version of Marlin firmware by default, the SD init fail error you see on the screen of your Ender 3 is the same problem as the Marlin SD init fail error, meaning that all the potential causes and solutions for the Marlin SD init fail error also apply in this case.
If you are currently using the stock firmware of your Ender 3, we highly recommend switching to the up-to-date version of the official Marlin firmware, as it offers plenty of improvements and fixes in comparison.
While seeing the SD init fail error message on the screen of your 3D printer can cause some concern due to it preventing the 3D printing process from moving forward, it’s a non-critical problem that won’t take a lot of your time to resolve.
To quickly recap, not having an SD card in the slot, an improperly formatted or broken SD card, a misconfigured or corrupted firmware, and a malfunctioning mainboard can all play a role in the occurrence of the SD card init fail issue in Marlin firmware.
As most of the typical culprits are either SD card or firmware related, pinpointing the problem and solving it should not be too much of a hassle and require a lot of your time or effort in any case other than the mainboard itself being broken.
Mike started his 3D printing journey with the Anet A8 when it first came out back in 2017, and has been obsessed with 3D printers ever since. Nowadays, he primarily uses his Ender 3 to print functional parts that make his life more convenient whenever possible.