Why is my SD Card Not Working?

Categories: News & Resources

Your SD Card is Not Working! Here are some quick steps to diagnose your SD Card before you replace it. It’s very likely the card still works! Usually, SD Card issues are easy to resolve.

Steps to fix your not working SD Card

Write Lock

The first thing you should do should always be the easiest! Looking at the face of the SD Card, there is a plastic switch on the upper left side. This is the Write lock. If the switch is down, it will lock the SD Card. Make sure the switch is up and unlocked.

Physical Damage to the SD Card

Look around the SD Card for any damage to the enclosure. It will be hard to tell if there is internal liquid damage but external visible damage to the housing or the connection pins will help determine if the card is still functional.

Card Reader/Adapter issues

The flimsiest part of any SD Card is actually the adapter you might be using with it. Check your card adapter for any damage. If all appears fine, try the adapter with a known good memory card. This will help you discover if the problem follows the adapter. Find replacement adapters on our website.


Sometimes the computer can be at fault. Disconnect the memory card and/or the memory card adapter and reseat it. If this doesn’t work, restart the computer. When the computer boots up again and you have logged in, plug the memory card or memory card reader into the computer again.

Compatibility Issues

In a set of circumstances, like specialty cameras or other devices, some SD Cards just don’t work with some devices. Before officially declaring your SD Card dead, look up any compatibility issues or limitations your card might have with the device you are using it with. Additionally, check to see if the suspect SD Card works properly in a different kind of device that you know works with known good SD Cards.

Reformat the SD Card

If you’ve tried all of the steps prior and your memory card still doesn’t work, this is most likely the issue. In some cases, your camera or device won’t recognize the memory card if it is improperly formatted. Most memory cards come formatted FAT32 or exFAT. Verify what kind of formatting your device needs to read and write to the memory card, or try formatting options at random. Format the memory card with your computer or device. Read more about how to format an SD Card here. NEVER format a drive without backing up the data first.

Replace your not working SD Card

If none of these solutions work, unfortunately your drive might be a bad unit. At this point, you will need to look at replacing your SD or MicroSD Card. Most manufacturers offer a warranty on their products and will offer replacement if it is covered under that warranty.

As for EBS, we offer a full refund on defective items on all sales made within 30 days of original purchase. Defective items discovered within 1 year of original purchase will be replaced at no cost. You can read more on our Terms and Conditions page.

Reasons your SD Card is not working

Write Lock Switch

The original SD Card featured a write lock! Why would you want to lock your SD Card? The lock uses physical protection to keep your card safe. If the lock is switched down, you’ll only have read access. Therefore, it is safe from being written to or erased. So, you will only be able to view the files on the card, not modify them.

Sometimes, it’s not always this easy. Damage to the switch itself can keep you from knowing if the switch is down. Or, you might not have access to the card because it’s stuck in a computer or camera. But, you can typically determine whether the card is locked by trying to modify a file on the card. For instance, if it’s in a camera, try to take a photo and see if it saves. Or, if it’s in a computer, copy files to the card. Write locking is when you can read the contents of a drive but not write to it.

Damage to the Card

We’ve already talked about damage to the write lock. Damage to the pins also causes functional issues. The pins on your SD Card are its communication medium to the computer. Electrons move from the computer to the card and back again and perform read/write tasks. Damaged pins impede this process. Keep an eye on any bending, corrosion, short circuiting, displacement, breaks or cuts, and missing pins.

Also, protect your SD Cards. The plastic housing of the SD card is relatively fragile. Make sure you are protecting from all scrapes, scratches, and avoiding any liquid contact. SD Cards are light enough to not worry about drops. But, you should always protect your cards in an SD Card case. We sell several accessories on our website to help. You can for shop them here.

Faulty SD Card Adapter

SD Card adapters are cheap and have a plastic build. As stated before, the flimsiest part of any SD Card is actually the adapter you might be using with it. Always have spare adapters for the inevitable when your adapter finally stops working. Having extra adapters will also help you troubleshoot where the problem in your connection is. A problematic adapter can cause data transfer issues like corruption or incomplete read/writing issues. The best way to avoid these problems happening is to backup your data and copy your pictures or files, never cut or move. Cutting and moving puts the only copy of your data at risk. Copy your files, then confirm their successful transfer, then delete the originals.

Computer Problems

Everyone has computer problems. Most issues with your computer comes from not restarting it frequently enough. A simple restart can resolve a lot of issues, especially with memory cards. When you plug your card into your computer with an adapter or into a built-in card reader, the computer mounts the drive. Sometimes, issues with mounting the drive to the operating system occur. Disconnecting the card from the adapter, adapter from the computer, card from the computer, or even restarting the computer resolves this issue.

Format Problems

As mentioned before, this is the most likely issue. In particular cameras, some devices are picky about what formats they can read and write to. You can format an SD Card in your camera or on your computer. If your camera is having issues writing to the card, the safest method is to format the card from the camera to guarantee it works with your specific camera. We wrote a helpful article here on how to format your memory card. If you do not have camera issues, you might have operating system issues. MacOS and Windows 10/11 don’t always get along. If you want to be able to read/write with both OSs, you’ll need to use exFAT. Just remember to backup your data before you format!

Defective Product

Finally, we’ve arrived at a defective product. We’ve all been there, a brand new product that was dead on arrival or one that’s been reliable for so long that it finally gave up the ghost. If you’ve been through all of these steps, then chances are your device is defective. You have a couple of options to work with…

Ordered through EBS

You will be given a full refund if you discover your new SD Card is defective and returned within 30 days. Defective items returned within 1 year of original purchase will be replaced at no cost. On our website, you can find the EBS full return policy.

Other options

Unfortunately, we can’t speak about the return policy of other companies. However, the original manufacturer will often provide a warranty long after the return policy of the company your ordered your SD Card from. For example, SanDisk gives a 5 year warranty on their SD and MicroSD cards. Replace your card through the manufacturer with the warranty.

Finally, you’re outside of the return policy and outside of the product warranty. I can safely say you got as much out of your SD Card as possible. It’s probably time to get a new one anyway. Flash memory cards move fast. Five or more years into the future and the technology inside the card, and even the technology outside of the card, has moved to become faster and more secure. You can shop for new SD Cards at the best prices on our website!

Unusual and Unique reasons your SD Card is not working

This article has an extensive amount of research that went into it. Please be careful thinking any of the below topics could be happening to your memory card. Because of the rarity of these issues it is highly unlikely you are experiencing the same thing. Nonetheless, keep an eye out for symptoms that may lead you to needing a manufacturer warranty replacement.

Richard Garrish

Memory Endurance

Your SD Card is divided into blocks that can only be erased one at a time. Erasing generally sets all bits in the block to “1”. Flash memory has a limited number of program erase (P/E) cycles. Most SD Cards are set to withstand ~100,000 P/E cycles before the endurance begins to fail and deteriorates the integrity of the drive. However, your flash controller has a tool called Wear Leveling that moves the data around the physical chip in hopes that the drive lasts longer and is worn evenly. For example, EBS sells SanDisk Industrial cards with high endurance ratings.

Read disturb

“Read disturb” is a result of how your computer reads NAND flash memory like an SD Card or flash drive. Different blocks within a NAND SD Card can only be read/written so many times. The block resets after a set number of read/writes. Transistors that are read frequently over time cause nearby blocks of transistor cells to be programmed, opening up a failure opportunity. The data block is fixed only when the controller moves the data to a new block and erases the old block, releasing it to the block pool. If the controller does not do this on time, a “read disturb” error occurs and data loss is possible.

Temperature Related Electron Detrapping

Long-term heat exposure causes data loss because electrons within your SD Card become excited and leave. An SD Card exposed to heat for long periods of time has a higher chance of having an electron gain enough energy from heat to detrap from the transistor.

X-ray Sensitivity

Unfortunately, some flash memory is sensitive to X-rays. X-rays can erase a programmed bit on an SD Card from a programmed “0” to an erased “1”. Thus, deleting or corrupting the data on a flash memory card. Now, manufacturers are making X-ray resistant SD Cards!

Final Thoughts

Hopefully this article gives you some insight as to why your SD Card might not be working. Treat your cards right and know the limitations of your specific drives and you’ll be able to lengthen the life of your SD Cards. Some operating systems are even able to check the health of a mounted drive.