SSD Troubleshooting for a MacBook Pro® Computer

Is your MacBook Pro computer with a Crucial® SSD extremely sluggish, crashing, failing to see your drive, or giving you an error when trying to format or reinstall macOS X®? Here are some troubleshooting steps to follow in order to figure out what is causing your problem.

A potential hardware issue in the MacBook Pro

An important step for isolating the source of your problems is to physically remove the drive from the MacBook Pro to rule out any potential internal issues in the computer itself. Please note that even though your old drive, or a different drive, might not be exhibiting any issues inside the MacBook Pro, this doesn’t rule out a potential hardware issue inside the system.

When removing your SSD, make sure to follow appropriate install guides. You can use one of our install documents on our Mac SSD support page. When the drive is removed, you will want to connect it with some sort of external drive enclosure, or a USB to 2.5-inch drive adapter cable like this one available at

After the SSD is physically connected externally to the Macbook Pro, you can hold the OPTION key down while turning the system on. If you already have OS X® installed to the drive, this will bring up Startup Manager and you can select the SSD (now an external USB drive) as your boot device. By selecting the SSD and pressing Enter, you can test the drive to see how it responds. Bear in mind that the SSD might be slower because it’s now working through the USB interface, but you should be able to have your desktop load and use any software you have on the drive .

If you are having problems booting to the SSD externally, or haven’t installed OS X to the drive, you will now want to follow the steps for erasing your SSD, then proceed with reinstalling the operating system.

If you can erase your SSD externally and install OS X to the drive, the SSD is functioning normally. If testing outside the MacBook Pro looks positive, you can install the drive back into the MacBook Pro to see what happens. However, if the system runs into problems after installing the drive, it is a potential hardware problem inside the MacBook Pro – possibly a malfunctioning ribbon cable or a logic board problem.

Another thing to consider is running Apple Hardware Test to see if it can catch any apparent memory problems or other issues. Be aware that hardware tests can fail running tests on healthy drives when they are behind a faulty ribbon cable, which is another important reason for testing externally.

Possible OS X issues

A problem with the operating system itself can potentially cause lots of different issues. A bad operating system can be a source of slow system performance, crashes, or loading errors. To rule out any possible OS X issue, try reinstalling the operating system. Back up any important data first, then follow Apple guidelines and remember to erase your disk before reinstalling.

In some situations, the recovery partition on a drive might be corrupt. If this is the case, you will need to use Internet recovery mode if you have a 2011-2012 MacBook Pro, or if you have a pre-2011 model, get an OS X recovery media on a DVD or flash drive.

A defective ribbon cable

A potential problem with MacBook Pro systems has to do with the black ribbon cable that connects to the internal drive. Over time, it’s possible for this cable to exhibit issues that interfere with the operation of the drive. These problems tend to be more prevalent with fast SSDs because they are utilizing 100% of the bandwidth on that cable. An older, slower HDD uses only a fraction of this bandwidth and can be more resilient to these problems. For this reason, if your old disk drive (or even a different SSD) is working fine on a cable, it doesn’t necessarily rule the cable out as a problem.

The important thing to remember: If you can see the SSD, erase the SSD, and transfer data to the drive outside of your MacBook Pro, or with it in another system, your SSD is most likely functional.

If it looks like the ribbon cable is the problem for your MacBook Pro, it’s something relatively easy to address. If you’ve already physically replaced your drive with an SSD, then it’s only a few extra steps more to swap your existing cable out. We recommend you look at a reputable Mac parts reseller online for purchasing a replacement cable. Buying a second hand replacement cable for a bargain price online is an easy way to get another defective one, so for this reason go through a reputable Apple parts dealer.

A defective SSD

If all of the steps above don’t result in a positive outcome, then we might need to look at replacing your SSD. Typically, if an SSD is defective it will give you errors when you try to erase/format the drive both internal and external on the MacBook Pro. If the SSD is simply not being detected no matter where it is installed, you will need to try our power cycle instructions to try and reset the SSD, but if this do not recover the drive, it will most likely need to be replaced.

If you recently purchased your SSD, please contact the place of purchase for replacement options. If you are outside the return period from the seller you bought your drive from, or you received it directly from, you can submit an online RMA request through our website or contact our support here and selecting your region.

©2019 Micron Technology, Inc. All rights reserved. Information, products, and/or specifications are subject to change without notice. Neither Crucial nor Micron Technology, Inc. is responsible for omissions or errors in typography or photography. Micron, the Micron logo, Crucial, and the Crucial logo are trademarks or registered trademarks of Micron Technology, Inc. Macbook Pro,macOS, and OS X are trademarks of Apple, Inc., registered in the United States and/or other countries. All other trademarks and service marks are the property of their respective owners.