Mac Os Flash Drive Read Onlycompubrown


Does your Mac not recognize a USB drive? Is the USB flash drive not showing up on Mac after inserting it in the USB port? Find solutions here. Download EaseUS Data Recovery Wizard for Mac when you want to recover data from a USB drive not recognized.

Mac Won't Recognize USB, What Should You Do?

I have a Mac 10.4.3 OS and followed your above method to reformat a 264 MB usb flash drive from Mac OS Extended (journaled) to EXFAT with no success. Tried 4 times, each time it came back Mac OS Extended (journaled). Any help you could offer would be appreciated. Intel-based Mac. Bootable USB thumb drive formatted with a GUID partition type and containing an OS X installer or a usable operating system. Let’s see how to boot a Mac from a bootable USB drive and what to do if your Mac doesn’t start up from it. Way 1: Boot Mac from USB Drive using Startup Manager. Getting your Mac to load from a USB. Select the External drive in the sidebar (the next step won't work if you only select the volume - in the screenshot above you would need to select the SanDisk, not the NO NAME). Numerous advanced tips can be used to make sure that the user gets the best results when it comes to USB usage on a Mac. This tutorial will discuss the top 7 tips for using a flash drive. It will also provide a basic level of training to make the overall use of flash drive easier for Mac users. 1 Connecting Flash Drive to MAC.

Commonly, when you insert a USB drive in the USB port on a Mac computer, the drive will soon appear on the desktop or hide in the Finder, letting you access, view, and manage data on it. Did you come across the situation that no matter how many times you try to connect the USB drive with a Mac computer, the USB drive is not showing up anywhere? Why this time Mac won't recognize a connected USB you may wonder. Though not a usual thing, the issue of an external hard drive or flash drive not showing up on Mac happens sometimes. What should you do in this circumstance? What are the effective solutions to make your USB drive show up again?

This page basically covers all the possible fixes for USB not showing up on Mac, which also applies to the similar issues of other storage devices like an external hard drive not showing up on Mac, flash drive not showing up on Mac, SD card not showing up on Mac, etc. Take a quick glance at the main content and directly jump to the part you're most interested in.

Workable SolutionsStep-by-step Troubleshooting
Fix 1~4. Some basic check and change settings1. Change the connection way
2. Change settings for desktop
3. Change settings for Finder
4. Check system information...Full steps
Fix 5~8. Repair corrupted USB drive1. Reset USB ports
2. Repair in Disk Utility
3. Repair with the terminal
4. Reformat USB drive...Full steps
Fix 9~10. macOS troubleshooting and manual repair1. update macOS and firmware
2. Manual repair service...Full steps

10 Fixes for USB Not Showing Up on Mac

The reasons behind the problem of a USB device not showing up are various, including the USB port is not working, USB drive corruption, virus infection, macOS faulty, etc. So, to figure out the effective solutions for your own case, you need to take time to have some basic check, exclude the irrelevant issues, identify the potential risk, and finally solve it!

As losing the access to data is the most direct impact of Mac not detecting a USB drive, you might need to perform USB data recovery on Mac.

Fix 1. Change the USB-to-Mac connection way

Have you tried to restart your Mac once or twice? Before taking further measures, don't forget the most efficient way to tackle commonplace hardware glitches that arises from time to time. If this operating system restarting fails to solve the current problem, move on to check the physical connectivity issue step by step.

Step 1. Plug the USB drive out from the not working USB port and change to the other USB port. Try all the available USB ports on your Mac.

Step 2. Did you use a USB connection cable or a USB-C adapter? If yes, take the USB drive out, and directly plug it in the USB port.

Step 3. Is there the other Mac computer available to you? If yes, try to connect the USB drive to this computer. Is it showing up normally?

Step 4. For SD card owners, the common way to connect an SD card to a Mac needs a card reader. If changing the USB ports did not work, try to change a card reader for a new round of tests.

The four steps of troubleshooting a USB drive not showing up on Mac are very basic, however, quite helpful in most cases. Each step can help us exclude the issues of a bad/loose connection, a not working USB port, a lack of power, and other superficial phenomenons.

Fix 2. Change settings for Mac detecting an external hard disk on the desktop

Occasionally, your Mac has already recognized the USB flash drive but not shown it on the desktop. Thus, you should go to Finder > Preferences > General and make sure the 'External disks' option is ticked. Then you'll see the USB flash drive showing up on Mac desktop.

Fix 3. Change settings for Mac recognize an external hard disk in the Finder

Finder is the other access for us to check a connected external drive on Mac. If your flash drive or external hard drive is not showing up there, go to Finder > Preferences > Sidebar, and under Locations, you need to tick the option 'External disks'. By selecting this option, we can make sure that the connected external USB hard drive or flash drive will normally show up in the Finder.

Mac Flash Drive Read Only

Fix 4. Check the USB drive in System Information

When you cannot find the USB drive on the desktop or in the Finder, try to look for it in the System Information section, which is usually a hidden place for average Mac users.

Step 1. Go to Applications > Utilities > System Information.

Step 2. Check if the system detects the USB drive. Click 'USB' on the left panel, and you can also check the USB flash drive information.

Fix 5. Reset USB ports on Mac to detect a USB drive

Step 1. Restart Mac computer, press the Command +Option+P+R keys until the Apple logo appears.

Step 2. Press Command+Option+Esc keys to close all applications that are not responding.

Step 3. Plug the USB which is not showing up to your Mac computer. If it doesn't show up, click Apple icon and select 'Sleep'.

Step 4. Wake up the computer after a few seconds by pressing any key.

Step 5. Shut down the Mac, unplug the power cord, reattach it after 15 seconds.

If this doesn't work, we should suspect the corruption issue at this moment. Don't give up and try to do some repair by yourself.

Fix 6. Repair USB flash drive with First Aid if it doesn't show up

Step 1. Go to Applications > Utilities > Disk Utility.

  1. Step 2. Select USB flash drive on the left panel of Disk Utility, and click 'First Aid' at the top toolbar and click 'Run'. Disk Utility will repair any errors on the drive automatically.

Step 3. Select the USB drive and click 'Unmount' at the top toolbar, unplug the USB and plug it back in 10-15 seconds.

Fix 7. Check and fix errors in a not recognized USB with Terminal

Step 1. Open Terminal in Utilities, type:diskutil list and press Return.

Step 2. Find the disk number of your USB flash drive, type: diskutil info disk2 and press Return. (Replace 2 with the disk number of your USB flash drive.)

Step 3. Type: diskutil eject disk 2 and press Return.

Step 4. Type: diskutil list and press Return.When the USB disappear from the Terminal list, close the window.

Step 5. Close Terminal and open Console to inspect your drive errors.

Step 6. Click 'Errors and Faults' to check if there are any errors.

Step 7. Reconnect your USB flash drive back to Mac, if no error shows up, your USB flash drive is safe.

Fix 8. Save data and reformat the not showing USB drive

Disk reformatting basically solves many hard drive issues, including the not showing up USB, particularly the time when you are able to see the USB icon but files are not showing. USB drive showing empty makes no sense, so you have to reformat the disk and make it usable again.

Note that reformatting will erase data. As long as the data matters, you need to follow the standard procedure to ensure zero data loss. [1] Download EaseUS Data Recovery Wizard for Mac, the professional Mac data recovery software, to perform a full USB drive data recovery. [2] Reformat the USB drive in Disk Utility.

To format the USB drive in Disk Utility:

Step 1. Go to Utilities and open Disk Utility.

Step 2. Select the not showing up USB flash drive in the Disk Utility sidebar.

Step 3. Click Erase on the top.

Mac Os Flash Drive Read Only

Step 4. Finish the necessary information (name, format, and scheme) to format the USB flash drive.

Fix 9. Update your macOS and firmware

Did your Mac's OS keep updating all the time? Chances are that your Mac won't recognize a USB drive, especially after a macOS update. This time, take a close look at the settings whether your Mac is up-to-date. Equally, firmware updates address a variety of hardware issues and the functionality of the USB ports could well be one of them. So, keep your software and firmware up to date will likely make the USB drive show up as normal again.

Fix 10. Send the USB drive to a repair center

Nowadays even the branded USB flash drives are not expensive. If you've tried all the suggested troubleshooting methods, the USB drive is still not showing up on Mac, you have to accept the truth that it's severely damaged and beyond your ability to repair it.

Mac won't recognize a badly damaged flash drive or external hard drive since there is no way to show it up, even temporarily, which makes the data recovery difficult. The last chance for you to rescue data is to send the broken USB drive to a specialized data recovery service center nearby, and let the professionals try their best. You need to prepare for the manual data recovery cost, which is noticeably higher than the software data recovery. Hence, always try the cost-effective plan of using EaseUS Data Recovery Wizard to scan the USB drive for the first attempt.

Step 1. Correctly connect your USB flash drive to your Mac. Launch EaseUS Data Recovery Wizard for Mac. Start selecting the flash drive and click 'Scan' to let the software search lost files on it.

Step 2. After a quick scan and deep scan, all files will be presented in the left panel in the scan results.

Step 3. Select files you want to recover and click the 'Recover Now' button. Don't save the recoverable files to the USB drive itself in case of data overwriting.

How to Fix USB Flash Drive Not Showing up on Mac – Fix External Hard Drive not Showing up on Mac:

USB Flash Drive Not Showing up on Mac: USB Flash Drive is a useful device for every computer user. It is helpful for storage and transfer of important data, files and documents. Some people use the USB flash drive(s) to take backup of their work, especially accounting, finance & tax related work. The flash drive provides so much help and convenience when it works properly. But it also creates trouble when it is not showing up. This can happen to anyone, at anytime. If your USB flash drive is not showing up on Mac, you have reached the right place. Here we provide complete information about USB flash drive and best ways to fix the issue when it’s not showing up on Mac.


  • 2 How to Fix USB Flash Drive Not Showing up on Mac

What is USB Flash Drive?

A USB Flash Drive is a small and portable storage device. It is also known as Memory Stick, Gig Stick, Thumb Drive, Jump Drive, Pen Drive and many other names.

The USB Flash Drive generally comes in very small size that you can carry it in your pocket or purse. Most flash drives don’t need power cable, they simply appear as you connect them to your Mac or other computer. However, some external hard drives come with 2 USB Cables or One USB Cable and One Power Cable. You must have at least one USB port on your Mac PC to connect the flash drive to Mac.

Need and Importance of USB Flash Drive

Most people use USB Flash Drive(s) to store their important files and documents or keep backup of precious data. You can also use the USB flash drive to transfer files from one computer to another. In addition to data storage and file transfer, the Flash Drive has some more uses. You can unlock your computer with help of USB Flash Drive. If you have forgot the User Login Password on your Mac or Windows PC, you need a Flash Drive to reset the password and access your computer.

How to Connect Flash Drive to Mac PC or Mac Book

You don’t need much tools for connecting a USB flash drive to your Mac. It comes with built-in USB Connector, so your Mac should have USB Port to plug-in the flash drive. You need to insert the USB flash drive into USB Port when the Mac is ON. The Mac Desktop will show up the USB Flash Drive Icon and Name as soon as it is able to read it. Once the USB Flash Drive appears on Mac, you can access all data stored on that flash drive.

Usb Flash Drive Read Only Mac

Why is My USB Flash Drive Not Showing up on Mac?

As you insert a USB Flash Drive into Mac, it should show up on desktop. In case you don’t see the Flash Drive Icon on desktop, you should search it in Finder. There is a problem if the flash drive is neither showing up on desktop nor in Finder. The flash drive not showing up on Mac can happen because of various reasons. Here we will discuss some common causes for flash drive not showing issue as under:

  • Plug-in Properly: When you plug-in a flash drive to Mac, do it gently. Do not put so much pressure that it hurts either flash drive or Mac USB Port. If the USB flash drive is not showing up on Mac, you should unplug it and plug it in again.
  • Check USB Cable/Connector: Flash Drive comes with USB Connector, you should check if it’s working. In case USB Connector is broken, the flash drive may not work on any computer. If you are using a USB Hub, make sure it’s working and try the flash drive in other port of USB Hub.
  • Mac USB Port is Faulty: Your Mac may have 2 or more USB Ports. Just unplug flash drive from current port and plug-in to other port. It will solve the problem if the flash drive is not showing up due to faulty USB port on Mac.
  • A Restricting App: If the flash drive was working on your Mac before a few days, you should check recently installed apps. Because there can be an App on Mac which is restricting the computer from showing up the flash drive. Just uninstall the new app, restart Mac and connect flash drive again to check if it’s showing up.
  • Mac is Not Set to Show: Sometimes your Mac Settings are changed without your knowledge. The flash drive not showing up issue can arise because the Mac is not set to show flash drive on desktop. You can change settings in Finder Preferences.
  • Flash Drive Not Formatted for Mac: Flash Drives are read by Mac, Windows, Linux and other OS computers based on their formats. If your flash drive is formatted for Windows PC, the Mac System cannot read it. As a result, your flash drive is not showing up on Mac. You can reformat the flash drive on Mac, but this process will erase all data.
  • Flash Drive is Corrupted: Mac System does not show up a corrupted flash drive. In case it detects that the flash drive is corrupted, it will simply ask you to format the drive and erase all data. If it doesn’t ask, still it is recommended to go to Disk Utility on Mac and Format the Flash Drive.

How to Fix USB Flash Drive Not Showing up on Mac

We have discussed the problem and causes for USB Flash Drive Not Showing up on Mac. Now we will move towards the solution. We have conducted a research to get best solution for USB flash drive not showing up on Mac PC. Here we will explain each and every method to fix flash drive not showing up Mac as follows:

  1. Check and Modify Finder Preferences (General and Sidebar)
  2. Mount Flash Drive Manually
  3. Run “First Aid” on External Drive to Repair Flash Drive
  4. Reset SMC on Mac
  5. Reset PRAM/NVRAM to Reset Mac USB Ports
  6. Fix Flash Drive Errors with Terminal
  7. Format Flash Drive (Erase All Data)

01. Check and Modify Finder Preferences

Mac OS is a highly efficient and versatile operating system. It provides plenty of features that are rarely used by Mac Users. Therefore people don’t change any settings in their Mac unless it is mandatory for them. When you plug-in your flash drive, it should show up on Mac desktop as well as in Finder. The flash drive is not showing up on Mac, that may happen because your Mac is set for not to show it. There are two options in Finder Preferences that can fix the issues of Flash Drive not showing up on Mac.

How to Check and Modify Finder Preferences:

01. On your Mac Desktop, go to Finder.

02. Select “Preferences” tab to open a new window.

03. Click on “General” Section and verify the “External disks” box is checked.

04. If not, check the box of External Disks under Show these items on the desktop.

05. Now select “Sidebar” section and check the box of External disks under Devices.

Your flash drive should be showing up on Mac after changing the Finder Preferences. In case it is still not showing up then you should mount the flash drive manually.

02. Mount Flash Drive Manually

Mac System is designed to detect the external drives and devices when they are plugged in. But sometimes it does not detect your flash drive automatically. In such circumstances, we recommend you to mount your flash drive manually on Mac. This process is very simple and you don’t need to have much technical knowledge for doing it.

How to Mount Flash Drive Manually on Mac:

01. Open Finder, Select “Go” option and click on “Applications.”

02. Select “Utilities” and open “Disk Utility.”

03. Click on your Flash Drive in left sidebar.

04. Click on “Mount” option given above the disk list.

05. As you press Mount button, the flash drive will show up on your Mac.

When you manually mount the flash drive, your Mac will detect it immediately. So this is the easiest way to fix flash drive not showing up on Mac issue. Thereafter you can open the flash drive and access all documents and files stored on it.

03. Run First Aid on External Drive to Repair Flash Drive

The Hard Drive built-in your Mac System is known as Internal Drive, while the Flash Drive that you plug-in to Mac USB Port is called External Drive. When you insert a USB Flash Drive in Mac, it should show up on desktop or as notification. In case the flash drive is not showing up on Mac, you should try to repair it. The Mac System has a disk utility feature that is helpful to check the disk for errors and repair it so that it starts showing up on your computer.

Steps to Run First Aid on External Drive on Mac:

In order to run First Aid on External Drive (Flash Drive), you need to open Disk Utility on Mac. You can search Disk Utility from Spotlight or go to Finder. Kindly follow the simple steps given below to run First Aid on your Flash Drive.

01. Make sure the Flash Drive is already plugged into your Mac System.

02. Open Finder from Mac Desktop and go to Applications under “Go” menu.

03. Select “Utilities” and click on “Disk Utility” option to open a small window.

04. Your Flash Drive will appear under External section in left sidebar.

05. Select your Flash Drive and click on “First Aid” option mentioned.

06. Click on “Run” button to run the first aid on external drive i.e. your flash drive for repair.

07. On completion of first aid process, it will show as “The Disk has been successfully repaired.”

08. Choose “Unmount” option and remove the flash drive from your Mac.

09. Insert the flash drive again after 15 seconds and now the Mac will be showing up your flash drive.

After running First Aid on external drive, there are two possible results. First is “The Disk has been successfully repaired” and Second is “The Disk Repair is failed.” It can also happen that your flash drive is partially corrupted. Your Mac will offer further options for disk repair failure. If it says “partially corrupted/broken”, you should choose more repair options to fix the problem.

04. Reset SMC on Mac

SMC stands for System Management Controller that plays an important role in Mac System. The SMC is responsible for various low level functions on Intel based Mac computers. These functions include battery management, thermal management, ambient light sensing, keyboard backlighting, sudden motion sensor, status indicator light and selecting external video source for some iMac displays. There are some circumstances when you have to reset system management control on Mac. One of such circumstances is flash drive not showing up on Mac.

How to Reset SMC on Mac

The procedure to reset System Management Controller on Mac is different for various Mac devices. Here we provide Mac System wise steps to Reset SMC.

Steps to Reset SMC on Mac Desktop Computer:

  1. Open Apple Menu and select “Shut Down.”
  2. After the Mac is completely shut down, unplug the power cord.
  3. Don’t do anything for 15 seconds.
  4. Plug in the power cord again.
  5. Wait for 5 seconds
  6. Turn on your Mac Computer.

Steps to Reset SMC on MacBook with Removable Battery:

  1. Go to Apple Menu and choose “Shut Down” option.
  2. Remove the Battery from MacBook.
  3. Press and hold the power button for 5 seconds.
  4. Reinstall the Battery in MacBook.
  5. Press the power button again to turn on your MacBook.

Steps to Reset SMC on MacBook with Non-Removable Battery:

01. Select Apple Menu and click on “Shut Down” tab.

02. After your MacBook is completely shut down, press Shift-Control-Option keys on the left side of keyboard and press power button at the same time.

03. Hold all these keys and power button for 10 seconds.

04. Release all keys.

05. Press the power button to turn on your MacBook.

Note: If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button. Please keep this thing in mind while resetting the SMC on MacBook Pro with Touch ID.

05. Reset PRAM/NVRAM to Reset USB Ports

On your Mac, PRAM/NVRAM is a small amount of memory that stores certain settings. These settings include sound volume, display resolution, startup disk selection, time zone and recent kernel panic information. Parameter Random Access Memory (PRAM) and Nonvolatile Random Access Memory (NVRAM) store same information on Mac. Therefore the procedure to reset PRAM and NVRAM is same. When you reset PRAM/NVRAM, it’s not harmful and some small issues like flash drive not showing up on Mac gets fixed. That’s why we recommend you to go ahead and reset PRAM/NVRAM on your Mac.

How to Reset PRAM/NVRAM on Mac:

01. Shut Down your Mac.

02. Press power button and immediately press and hold these four keys together i.e. Option-Command-P-R.

03. Keep holding all four keys and release them after 20 seconds.*

04. Let your Mac PC or MacBook start itself.

05. Your PRAM/NVRAM has been Reset successfully.

*On Mac computers that play a startup sound, you can release the keys after hearing the startup sound for second time.

*On Mac computers with Apple T2 Security Chip, you can release the keys after the Apple logo appears and disappears for the second time.

06. Fix Flash Drive Errors with Terminal

Terminal is a command window on Mac computers. You can use Terminal App to execute commands and run tools as well as specify files and folders. With help of Commands in Terminal App, you can fix many issues on your Mac. When a USB Flash Drive is recognized by Mac but it’s not showing up, you should try to fix such errors with Terminal.

Steps to Fix USB Flash Drive Errors with Terminal:

Before you begin the procedure, make sure the flash drive is plugged into your Mac.

01. Go to Finder, select “Go” and click on “Applications” tab.

02. Navigate to Terminal App and click on it to open. (Open Terminal in Utilities.)

03. Type diskutil list and press Return button.

04. A list of disks on your Mac will be displayed on screen.

05. Navigate to the information given as /dev/disk2 (external, physical). In this step you should replace “2” to the disk number as shown on your Mac.

06. Check the information and type diskutil eject disk2 and press Return. Remove the Flash Drive from your Mac.

07. Again type diskutil list to check if the flash drive is ejected or still there.

08. Once the flash drive disappears from Terminal, close the window.

Check Errors and Faults in Flash Drive with Console:

This procedure starts right after closing the Terminal window.

  1. Go to Finder>Go>Applications and select “Console” to open it.
  2. Click on “Errors and Faults” tab to check for errors in your flash drive.
  3. Plug-in your flash drive to Mac and see the Console for errors.
  4. If No errors appear, your flash drive is safe and should be showing up on Mac.

After going through both the procedures with Terminal and Console, your flash drive must be showing up on Mac. In case it is still not showing then there can be only one reason i.e. The flash drive is corrupted.

07. Format the Flash Drive

You can fix the flash drive not showing up on Mac issue with one of the techniques we have shared above. However, there is no guarantee that one technique must fix the problem. You need to go through trial and error method to know which technique can solve your issue. If your flash drive is corrupted then it will not open on Mac or any other computer system. In such circumstances, you have to format the flash drive and erase all data on it.

Recover Data from Corrupted Flash Drive

There are some third party apps which allow you to recover data from a corrupted flash drive. If the data on your flash drive is very important then you should use “Disk Drill” or any other app to recover your data. Please note that these third party apps come with a certain price that you have to pay before using them on your Mac.

How to Format Flash Drive on Mac:

01. Press Command+Space Bar keys on your Mac Keyboard.

02. Plug-in the Flash Drive into Mac System.

03. Go to Finder, click on “Go” and Select Applications.

04. Click on Utilities and Open Disk Utility.

05. Select your Flash Drive in left sidebar under External section.

06. Click on “Erase” icon and Erase All Data on Flash Drive.

Final Words:

All the information mentioned above about How to Fix Flash Drive Not Showing up on Mac is true and fair. The methods to solve the issue of flash drive not showing up are working on Mac PC and MacBook. In case you have more queries regarding the flash drive not showing up on Mac, kindly contact the Apple Helpline at 1-800-MY-APPLE (800-692-7753) or visit Apple Support Website at support.apple.com.