Ender 3 Not Reading SD Card: How to Fix

Can’t start a print from your Ender 3? You’re not alone!

While not super common, many users have had issues with starting prints on their Creality Ender 3 (Pro/V2/S1) from the inserted MicroSD card. This can happen for a few different reasons, including, but not limited to, a MicroSD card that’s too large, improper formatting, and even too long of a file name.

Luckily, you can easily solve the problem and get your Ender 3 to read the inserted SD card (or another memory device). After checking the orientation of the MicroSD card (it happens to the best of us), I suggest reformatting the SD card, adjusting the internal partitions, and physically cleaning the card. There are a handful of other potential solutions too!

If you want to hear about all of the possible solutions for your Ender 3 not reading the SD card, just keep reading!

Why Does it Happen?

Before we dive into possible solutions, it’s worth going over why this actually happens. As I mentioned, the Ender 3 (as well as other 3D printers) might have trouble reading a MicroSD card for a handful of different reasons.

I won’t go over all of the possible causes of this problem, but it’s important to note that these causes are either physical or digital.

The physical causes, such as dirt or grime on the copper plating of the MicroSD card, are a little bit more tricky to solve because the damage might be permanent.

But, the digital causes, which are the more likely culprit of the problem, can be solved. Examples of digital causes for the Ender 3 not reading the SD card include improper formatting of the memory device, overly long file names, and poorly-set partitions.

How to Fix SD Card Not Reading

Now that you know some potential causes for your Ender 3 not reading SD card, it’s time to dive into the solutions. Just as there are many possible causes of this problem, there are also many solutions you can test out, which I’ve gone over in the sections below.

You’ll likely have to test a few different solutions until you solve your problem, but don’t lose hope. Just try one out, and if it doesn’t work, move on to the next one!

1. Correctly Insert the SD Card

First, make sure that you have correctly inserted the MicroSD card into your Ender 3’s respective motherboard port.

I know, I know…you’re thinking, “I’m not that stupid”. But, hey, it happens to everyone. Just double-check that the MicroSD card is oriented the right way when you insert it into your 3D printer’s motherboard.

For reference, the correct orientation of the MicroSD card depends on the specific version of the Ender 3 that you have, but it should click in smoothly.

2. Insert SD Card When Power is Off

Next, you can try inserting the SD card into your Ender 3’s motherboard when the power is turned off on the printer. This might work if, for some firmware-related reason, your Ender 3 is only checking the SD card memory on start-up.

Once you put in the SD card, wait a few seconds, and then turn on the printer (by flipping the power switch), and then check if you can access the files on the SD card from the printer’s LCD interface.

3. Adjust Partitions

Partitions are internal separations in a memory device’s storage. If the SD card you’re using has previously been used for running an OS, then it’s likely that the partitions are causing issues. That’s because some OS image flashing programs, by default, create unnecessary partitions on MicroSD cards.

You can view and adjust the partitions of a MicroSD card by first inserting the SD card into your computer (e.g. laptop, PC) and going to the Disk Management settings menu. On Windows computers, you can find this page by clicking the Windows button and searching for “partition”. It should be the first result.

Once on the Disk Management page, find your SD card from the list of storage devices. Then, you might notice partitions (rectangular sections) to the right of the name of the SD card. There should only be two partitions on your SD card.

If you have more, then start by moving all of the useful files on the SD card to another memory device (temporarily). Then, on the Disk Management page, right-click each partition and select “Delete Volume”. Do this until all of the sections are turned into one large section that has no volume.

After this, right-click the empty volume and click “New Simple Volume”. On the pop-up menu, click “Next”, and then look at how many MB are available in the volume.

Now, subtract about 1,000 (it can be basically any number above 0) from this number and enter that into the box titled “Simple volume size in MB”. Note that the smaller number you enter into this box, the less storage will be available on your SD card.

Next, click the “Next” button and finish the partition adjustment. Now, on the Disk Management page, you should see your SD card, with most of the storage assigned to a simple volume and a small amount left unassigned. This unassigned amount, for some reason, helps with allowing the Ender 3’s motherboard to read the SD card.

4. Rename G-Code Files

Another odd reason your Ender 3 might not be reading your inserted SD card is if the name of the G-code files are too long. Luckily, it’s a simple fix.

Just go into your computer’s file explorer and make sure all of the names of the files, including both G-code and non-G-code files, are not too long. I suggest keeping the names under 10 characters long, minus the “gcode” file extension part.

5. Use an SD Card with Less Storage

Many users have reported that using more spacious SD cards, like 64 GB+ cards, can cause the Ender 3 to be unable to read the files stored in the card. This problem has mainly been observed on versions of the Ender 3 with 8-bit motherboards, but it might also be the problem for 32-bit versions of the printer.

As such, try to use a MicroSD card that’s no larger than 32 GB. Of course, 32+ GB SD cards should work just fine, but, for some unlucky printers, it might not.

6. Clean SD Card

Cleaning a microSD card for the Creality Ender 3 is a simple process that can help ensure that your printer is able to read the card properly. To clean a microSD card, you will need a soft, dry cloth or a can of compressed air.

First, turn off the printer and remove the microSD card from the card slot. Then, use a dry cloth to gently wipe the copper contacts on the bottom of the SD card. Make sure to remove any dust or debris that may have accumulated on these contacts, as this is where the data from the memory device is read by the Ender 3’s motherboard.

If there is stubborn debris, whip out your can of compressed air to blow it away. Using a Q-tip also helps.

Once you’re done cleaning, reinsert the card into the printer and test it to see if the problem is resolved.

7. Clean Ender 3’s Motherboard Port

Another potential issue is the SD card slot on the Ender 3’s motherboard. Sometimes the SD card slot may be dirty or damaged, which can prevent the card from being read properly.

To fix this issue, you can try cleaning the card slot with a soft, dry cloth or a can of compressed air. If the card slot is damaged, you may need to replace it. I’ll go over more about this in a later section, though.

8. Format SD Card

Next, another super common cause of this issue is that the microSD card may not be formatted properly. The Creality Ender 3 requires that the card be formatted in FAT32 format, and if it is not, it may not be able to read it. To fix this issue, you can reformat the card using a computer using the steps below:

  1. Open your computer (e.g. laptop, PC), with the SD card inserted.
  2. Go to the file explorer.
  3. Locate the SD card drive in the file explorer.
  4. Right-click on the SD card drive and right-click.
  5. From the drop-down menu, click format.
  6. In the respective box for “Format”, choose “FAT32”.
  7. Click “Finish”, and wait for your computer to format the MicroSD card.

Now it should work!

9. Update the Firmware

Another reason for the Creality Ender 3 having problems reading the microSD card is the firmware, which runs on the printer’s motherboard. If the firmware on your printer is outdated, it might contain bugs which could affect the board’s ability to read the inserted MicroSD card. As such, you should update the firmware on your Ender 3’s motherboard.

The process for flashing a new firmware package depends on what motherboard your Ender 3 has installed. For 32-bit boards, like the Creality V4.2.2 or V4.2.7, you can install the new firmware by simply uploading the BIN file for the firmware package to the MicroSD card. But, for older 8-bit Ender 3 boards, the process is a little bit more tricky and involves using a separate Arduino board to serve as a bootloader.

Check out our article on updating firmware for your Ender 3 to learn more.

Alternative Solutions

The solutions I went over in the above sections should have helped you solve your problem. But if your Ender 3 is still not reading SD card devices, then here are some alternative solutions. They’re not fixes for the actual problem, but they are workarounds that will allow you to keep printing:

1. Replace the SD Card

First, the problem might come from the SD card itself. We all know that the Chinese manufacturers of consumer-grade 3D printers aren’t known for their attention to detail or quality, so it’s not surprising that users have reported that some of the MicroSD cards that come with their budget 3D printers eventually fail.

If you’ve tried every other solution and nothing is working, it might be time to replace the MicroSD card. Luckily, these memory devices aren’t expensive, and you can buy an 8 GB MicroSD card for under $10 on Amazon. And, if you do plan on buying a new MicroSD card, I strongly suggest getting one from a reputable brand like SanDisk.

2. Replace the Motherboard

Next, replacing the motherboard is necessary if the issue is caused by a hardware failure on the motherboard rather than the SD card or a digital issue. Sadly, this alternative solution is a bit expensive (around $40), but that’s also why I listed this option near the end because I wouldn’t want you to waste money if another solution worked.

The first step in replacing the motherboard is to unplug the printer and remove the cover. Then, locate the motherboard and disconnect any cables or wires that are connected to it. 

Next, remove the screws that hold the motherboard in place and carefully remove it from the printer. Finally, place the new motherboard into the housing, reconnect all the cables, and then test the printer with your SD card to see if the issue is resolved.

3. Use OctoPrint

OctoPrint is an open-source software that allows you to control your 3D printer remotely using a web interface. You can use OctoPrint, as well as other printer control servers (e.g. Klipper), to start prints on the Creality Ender 3 without an SD card.

Moreover, on OctoPrint’s web interface, you can upload your 3D model files directly to the printer over a network connection, eliminating the need for an SD card. So no problem if you weren’t able to solve your SD card reading issue!

Of course, there is a downside to using OctoPrint; you have to start prints off of the web interface and not the LCD on your Ender 3. Additionally, to use OctoPrint with your Ender 3, you will need to install it on a computer board, such as a Raspberry Pi, and connect it to your printer via a USB cable. Once connected, you can access the web interface to control the printer and start prints by typing in the IP address of the host computer board into your computer’s web browser.

Check out our article on setting up OctoPrint for your Ender 3 here.


The Creality Ender 3 is one of the best budget 3D printers around. But, as everyone knows, there are a lot of issues that can happen on this printer, as well as other low-cost 3D printers. One extremely annoying problem is when the Ender 3 can’t read the SD card inserted into the motherboard, preventing you from printing your G-code files.

This can happen for a few reasons, such as a debris-ridden SD card, long file names, too many partitions, and other causes. But, just as there are many potential causes, there are also many potential solutions.

First, I suggest making sure you orient the SD card correctly when inserting it into the motherboard slot. After you check this, if the printer still can’t read the SD card, try reformatting the MicroSD card in the FAT32 format and also check that there are only two partitions for the SD card.

If the issue persists, you can try cleaning the SD card as well as the motherboard port. And if your Ender 3 is still not reading the SD card, you might just want to make the $10 investment in a new MicroSD card for your printer.

Hope this helps!

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