04-07-2018 01:38 PM
Consider this a "me-too" reply. I bought a 500GB MX500 through Amazon to replace the HD on my mid-2012 13" MacBook Pro. The only way I could format it was by mounting the SSD in an external SATA dock. After rebooting and restoring it from my internal (original) HD I was able to boot but could not perform any "write" actions to the SSD (e.g., tried creating a simple text file but it would not save). Spent the better part of today at the local Apple store running diagnostics (all clean) and trying to just get a clean install of MacOS. No luck. They tried using APFS and Mac OS Extended (Journalled). All efforts undertaken have been with macOS 10.13.4.
I must say it was very snappy to boot. Looking forward to a solution.
04-08-2018 12:23 PM
Can you confirm the MX500 is installed in the hard drive bay or the optical drive bay?
Is the MX500 using a GUID partition format (check at bottom of Disk Utility)?
What needs to be done is to find out if this is a hardware issue between the Apple laptops and the MX500 SSDs or if it is just an OSX issue. I suggest downloading a Linux Live CD/USB image such as Knoppix to put on a bootable USB drive. You can try using Etcher to "burn" it to a USB drive (I just came across this app, but never tried it).
Make sure the MX500 is installed internally, power on the laptop and hold down the Option key to get the boot picker menu. Select the orange icon which may be labeled "EFI" or "Windows" and allow it to boot to the Knoppix Desktop. At the Knoppix desktop, click on the "Start" menu in the lower left and look for an application called "Disks" or "Disk Utility". In this utility, click on the MX500 or select it from a menu (may be identified as "sda" or "sdb") and delete all the partitions on the drive. Then create a new partition with FAT32 as the filesystem (make the partition somewhat small like 20GB). If you have a choice to select a partitioning style select GPT.
After creating the volume open a file explorer (the file cabinet icon on the Taskbar) and click on the new volume in the left pane of the file explorer to mount & view it. Click on the File menu and select "Create New....--> New Folder". Then do the same thing but choose "Empty File" (give it a name and add a ".txt" extension). Double click on it in the file explorer to open a text editor and add some text to it, then click "File --> Save". Close the text editor, then double-click on the file again to verify the changes were saved. Eject the MX500 using the left pane of the file explorer. Press the Caps Lock key so it is lit, then click on the "Start" menu and select "Logout" then Shutdown. Wait for the caps lock key LED to go dark.
Now boot to your original hard drive which should be in your external dock using Option boot. Now see if you can view the created file & folder. Then try editing or creating another file. If you cannot do so, then it appears to be an OSX issue. If you can now write to the drive, then use OSX Disk Utility to Erase the drive and see if OSX can write to its own volume on the MX500.
If you are unable to delete & recreate the partitions on the MX500 when installed in the internal hard drive bay using Knoppix, then it appears to be a hardware issue with Apple and the MX500. As a last ditch effort I would try a Secure Erase on the SSD and try again A Secure Erase will reset the SSD to factory defaults in case the SSD was left in some kind of odd state when you received it. You may be able to use Parted Magic to Sanitize/Secure Erase the MX500. I've never used it personally and it may not work on all systems. If it is unable to do so, I can provide you with instructions to try a Secure Erase using Linux.
If after trying all of this you still cannot write to the MX500 when installed internally, you should contact Crucial Support to report the issue and present the results of the above tests so they may be able to investigate the issue further to provide a solution or to mark Apple hardware as incompatible. Please update this thread with your results.
FYI, when using High Sierra (OSX 10.13.x) Disk Utility will not show empty drives in the interface. You need to select the "View All Devices" from the menu above the left pane in Disk Utility. If it doesn't show up after selecting "View All Devices", then close Disk Utility and reopen it and it should show a blank drive. You can access Disk Utility from the OSX installer once the menubar appears after selecting your language. Disk Utility is under the "Tools" or "Utilities" menu.
04-10-2018 07:02 PM
Thank you so much for the detailed reply. I solved my problem by taking the most simple course of action first, though. I bought/installed a new SATA cable and then restored from the old HD using Disk Utility. I've been up and running for about an hour and haven't found a task that I can't do. Marked improvement in speed, too, of course. The takeaway from the experience is that, despite the successful diagnostic runs at Apple, spend the $20 and replace the SATA cable before spending a bunch of time otherwise.