Make sure your BIOS/UEFI memory & CPU settings are set to Auto or Defaults since the new module may not be able to handle any custom settings.   You could also try clearing the BIOS/UEFI settings and setting them all back to defaults just in case something odd happened with them.   If these are set to Auto/Defaults, then it sounds like you may have received a defective module.   You could chat with Crucial Support to verify you did receive the correct module for your system.  I don't think you will have any problem getting it exchanged. ... View more

You could try updating the firmware on the SSD as an update was just released a few days ago.  It would be easiest to update it using your Windows PC (it needs to be installed internally or with eSATA).   With Windows you can either install Crucial Storage Executive to assist with the firmware update or you can download an .iso updater which can be burned to CD (it is also possible to "burn" it to a USB drive, but I'm not sure it is possible to do this using Windows). ... View more

Have you tried removing all memory &  installing just one new stick at a time in the same slot to see if one of the new modules may be bad?      Have you tried installing doing the same with the other slot?   This will identify if one of the slots might have an issue.   If you reinstall the original memory, does the system work properly?   Try an SMC & PRAM reset with the new memory installed to see if it solves your problem.   With the PRAM reset, let it cycle about three times (look for your screen to flicker slightly) or hold the keys for about a minute (screen should be black or gray with no text or icons).   What version of OSX are you running?   Did you order the memory using a link provided by the Crucial Advisor Tool or Crucial System Scanner?  If not, you may want to chat with Crucial Support to confirm the memory you purchased is compatible with your iMac.  Even if you purchased it from a recommend link, there is always a slim chance you were sent the incorrect part.   Try running the Apple Diagnostic with the new memory installed.   You might want to try running Memtest86 as well (you can try using Etcher to create a bootable USB drive for Memtest86).  If it shows errors, try one new stick by itself to see if you can isolate which stick or slot might be at issue.  Also try Memtest86 with the original memory just to make sure it works without any errors on your system.   I haven't used Memtest86 enough to know how compatible it is with Apple systems.   These tests may not find any issues, but if they do it may be easier to reproduce problems than using your system normally and it eliminates possible software issues.       ... View more

Are you saying it will boot the Windows installation if your Windows installer disk is connected to the computer?  If so, boot to the Windows installer, then click "Repair this Computer" link in the lower left after selecting your language in the Windows installer.  I think you then select Troubleshooting, then select Advanced, then Startup Repair which should automatically check for boot issues and repair them for you.   If I'm misunderstanding please clarify if you modified the partitions after Windows was installed or is the issue because of the way you partitioned the drive before installing Windows?   How did you create or modify the partitions and can you give us a list of the partitions with their type & formatted filesystems and labels?     Is the drive partitioned as MBR or GPT?   Did your new Windows installation ever boot on its own?  Is there only one OS on this system?   If you modified partitions after Windows was installed, you might find it easier to just reinstall Windows depending on your setup. ... View more

The hard drive cable replacement came in relatively late so I'm not sure it was active at the time of your repair and it was only for the 13" model.   If you disconnect the cable from the Logic Board, and look on the back side the "part number" of the cable should be 821-00698-A (at least this is on the official ones I have).   It might be a good idea to disconnect it from the Logic Board anyway, blow some compressed air on the connectors (cable & MLB) and reseat it.    These cables are not expensive so I would try to find a new one from a reputable source.   If you boot using Internet Recovery, can you see the MX500 with the USB enclosure?  If so, see if you can run Disk First Aid on it using Disk Utility.   There is also the possibility that APFS is not playing well with the MX500.  You could try reinstalling OSX 10.13 with APFS disabled.   You need to edit the installer to force it to use HFS+ (journaled).   If you try downloading and running the installer from your hard drive with the older version of OSX, you should be able to point the installer to your external MX500 assuming the drive is physically seen.   If you connect the MX500 using your USB enclosure, you can try issuing the following command from the Terminal app to see if the drive is physcially seen by the system: diskutil list This will list all physical & logical volumes detected by the system.   Disk0 & 1 will most likely be your internal drive & mounted volume.   Assuming no other connected/mounted drives, CDs, iOS devices or .dmgs,    "disk2" will most likely be your MX500 and you should be able to tell by the size or possibly volume name.   If you have another computer you could try installing it there to see if the drive is physically seen using the above method to detect the drive or using Disk Management if it is a Windows system. ... View more

@kgcode, Check your other hard drive for errors as well.   If it is having issues, it can affect the cloning process.   Not all drives have each of those attributes, but if they exist and are non-zero it could be the reason for the cloning issues or even rebooting issues.  Unfortunately not all hard drive issues are reflected in the SMART Attributes.   Is there a BIOS/UEFI firmware update available for your system/motherboard?     If you decide to make another clone, I would suggest performing a clean install of Windows 8.1 first and see if it resolves your problems (make sure to install the system/motherboard chipset & SATA drivers and possibly Intel drivers).   You can download the Windows installer direct from Microsoft.   Depending on your system, it may even be possible to reinstall Windows over top of itself without affecting your data.  Microsoft is very particular in the rules for this for some reason, so most likely the option won't be available to you.   Just on the off chance your new SSD is having issues, you may want to post a screenshot of the SMART Attributes for the MX500.   If your laptop uses a SATA cable, then it may need replaced.   The reinstall Windows option is a good way to narrow down the possible failure points. ... View more

It sounds like the hard drive cable in your laptop needs replaced.   With the 13" (mid 2012) model, the hard drive cables were notorious for failing, so much so Apple actually had a  free  replacement program which expires three years from date of purchase.    To confirm the cable is the  problem , try   Option Booting  your MBPro with the SSD connected with a USB  to SATA Adapter .   Your old version of OSX will not see the new SSD due to the use of APFS so booting externally is your best option.     FYI, some USB adapters may not always be compatible, but if it does work you know for sure.   I've personally seen very weird behavior with these failing cables on this model.    ... View more

It sounds like the hard drive cable in your laptop needs replaced.   If this is a 13" (mid 2012) model, the hard drive cables were notorious for failing, so much so Apple actually had a free replacement program which expires three years from date of purchase.    To confirm the cable is the problem, try Option Booting your MBPro with the SSD connected with your USB enclosure.   Your old version of OSX will not see the new SSD due to the use of APFS so booting externally is your best option.     FYI, some USB enclosures may not always be compatible, but if it does work you know for sure. ... View more

@kgcode,    My guess is one of your original hard drives may be failing and Acronis was having trouble due to the errors.   In my experience most cloning software has trouble when the source drive is slow or failing, but if the other hard drive is failing it can cause interference on the SATA controller causing issues you described.   You should be able to see if this was the case by checking both hard drive's SMART Attributes. You can use GSmartControl to check it and they have a portable version so you don't have to actually install anything.   You should be able to check your original boot drive by connecting it externally with your USB to SATA cable, although some USB controllers & adapters may block access to SMART.   Check that the RAW value for the following SMART Attributes is zero:   5      Reallocated Sector Count 187  Reported Uncorrectable Errors 196  Reallocated Event Count 197  Current Pending Sector Count 198  Uncorrectable Sector Count   188  Command Timeout 199  UltraDMA CRC Error Count   (usually indicates a cable issue)   Sometimes SMART errors may be listed below the SMART Attribute table (some GUI's don't include them though) which may not always be reflected in the attributes I listed.   FYI to everyone, if your system is slow or you suspect your hard drive is failing you need to be very careful.  The more you keep trying things, the more likely the failing hard drive will get worse to the point where your data will not be recoverable even with professional data recovery services (most people I find don't have any backups).   The best free tool I've ever used to clone a failing hard drive is the Linux gddrescue command line tool.  Here is a nice overview of the process.   In addition to the gddrescue options listed in the link, I would add the following "--ask" so it gives you one chance to make sure you got the source & destination correct.   ... View more

@latrino,   In order to "dd" Crucial firmware .iso file you need to run "isohybrid" on it.  By default Crucial's files are created only for burning CDs.  Running  isohybrid on it allows it to be "burned" to a USB flash drive or hard drive for Legacy MBR booting.   isohybrid is part of the syslinux-tools package on Debian based distros.   If you need to boot from a UEFI only system, then you need to manually copy the contents of the .iso file to a FAT formatted USB drive and install GRUB2 to it and create a grub.cfg file with the kernel boot parameters found in the /boot/isolinux/isolinux.cfg file.   You can follow my instructions from this post and delete the "rssd-model=MX200" option from the grub.cfg I listed in that post.   I was using Debian 9 "Stretch" to make a bootable MX200 updater.   If your Linux distro has trouble installing GRUB2 to the USB drive then follow these instructions:     Install "schroot" and use "debootstrap" to install Debian 9 Stretch (add "sudo" as an extra package to install to make life easier).   Debootstrap is a script provided by Debian which can run on any Linux system IIRC.   The schroot creates a private Linux install that can still access your home folder.   Most things you do in the schroot will only affect this new environment although there are always exceptions so when finished make sure to exit it.   In the schroot, install "grub-efi".    Mount your USB drive in the schroot and run the grub-install command I provided and modify the grub.cfg as noted above.  Afterwards unmount the USB drive from both the schroot AND from your main system.        ... View more

@djoser   I'm just a regular Crucial customer such as yourself.  I just happen to have an interest in boot issues such as this one.   I was able to make a UEFI bootable USB drive for the MX200 firmware updater using Linux.   These instructions assume your Linux system is currently booting using UEFI.   1)  Create a FAT partiton on your USB drive using either MBR or GPT.  If your system won't boot, then try using the other partition type.   The partition type can be either "W95 FAT32 (LBA)" or "Microsoft Data" (respectively).   2)  Mount the FAT partition on your USB drive at "/mnt".  All of the instructions here will assume it is mounted at this location.     3)  Mount the MX200 firmware updater .iso file and copy all of the files within the .iso to your USB drive at "/mnt".   4)  Install the GRUB2 EFI boot files to the USB drive.  This command only works from a UEFI booted Linux system as it requires a grub-efi installation.   Using the terminal command line issue the following command: sudo grub-install -v --removable --boot-directory=/mnt/boot --efi-directory=/mnt --target=x86_64-efi --no-nvram Note:  If the above command is not done properly, it could make your system unbootable.   Make sure to have your Linux installer available so you can fix any issues.   The command I provided can be copied and pasted as is as long as your USB drive is mounted at "/mnt".   Note #2:  The "--no-nvram"  option should keep the GRUB installer from modifying your system's UEFI boot menus.   5)  Create a GRUB configuration file on your USB drive in /mnt/boot/grub/grub.cfg.   # GRUB2 Configuration file for Crucial MX200 MU05 Firmware Updater # Configuration file location on USB drive: # /boot/grub/grub.cfg # insmod all_video menuentry "Crucial MX200 MU05 Updater" { linux /boot/vmlinuz libata.allow_tpm=1 quiet base loglevel=3 waitusb=10 superuser mse-iso rssd-fw-update rssd-fwdir=/opt/firmware rssd-model=MX200 initrd /boot/core.gz }  Note:  The "linux" line should be all on one single line.   I got the options from the "isolinux.cfg" file from within the .iso image at "/boot/isolinux/isolinux.cfg"   6)  Unmount your USB drive and reboot your system.   Bring up your system's boot menu during system POST and you should see a UEFI USB boot option for your MX200 updater.   If not, disable Secure Boot.  If it still does not appear, enter the BIOS/UEFI settings and manually create a system UEFI boot entry for your USB drive.  The boot file needed is located at "/EFI/BOOT/BOOTX64.EFI".   Save & reboot and you should now see your USB drive as a boot option.   I was only able to test the resulting USB drive on a MacBook which uses UEFI.  Crucial Storage Executive runs and determines I don't have a MX200 drive installed which is correct.  I believe it should have no problem updating your MX200 as long as your SATA controller is set to AHCI mode.   If you have any problems, let me know and provide information on the failure and what happens during the boot attempt.   Good Luck and update this post if you are successful so others will know it works. ... View more

@djoser,   I believe it may be   possible to modify the updater to boot to a UEFI only system.   I'll see if I can make a little time to try it out.   Since you are using Linux, I believe you can make a flash drive using GRUB2 to boot the    .iso file itself.    I've seen info on this but never tried it.   I also don't know if it will work on a UEFI only system. ... View more

The SMART Attributes in your screenshot are similar to several of our MX300s.    I don't recall exact numbers, but I believe I had 26 Reallocated Blocks and I forget how many thousand Uncorrectable Errors, but I was shocked.    The Uncorrectable Errors accumulated because the SSD got stuck reallocating the bad blocks while it was using the older firmware.  The one SSD was part of a software RAID which broke which is how we discovered the issue initially.  After updating the firmware & performing a Secure Erase, we haven't had any more issues with the RAID.     The other MX300s we use are in laptops, and I don't recall anyone reporting issues to us, but I'm not always made aware of the reports either.   We caught the next one when a SMART monitoring utility told us about the bad block.  The others I proactively upgraded and in some cases Secure Erased just to be safe.    We've also disabled power saving options in the OS for the MX300 as well and I think the latest firmware did the same IIRC.     Keep an eye on the Uncorrectable Errors attribute.  I've only noticed this attribute increase while there are Pending Blocks to reallocate.   I actually watched the Uncorrectable errors increase while the SSD was sitting idle & unmounted when it had several pending blocks to reallocate.   Perhaps the issue you have is the bad blocks are not being realloated quickly enough which is causing your performance and other issues.  Perhaps if you monitor when a bad block occurs and how soon after it is actually reallocated might help your cause in getting an RMA if it is affecting booting & performance.   If after the Garbage Collection you still accumulate errors, I would Sanitize/Secure Erase the SSD and see if that solves your problems.   Personally I think the SSD needs that reset to overcome whatever occurred with the old firmware, but that's just my opinion.       I think everyone feels the same way about bad blocks since we've been trained to fear them after dealing with hard drives.  With hard drives it almost always meant an imminent failure and it would severely affect performance.   I keep a close eye on our SSDs' Reallocated Blocks to study how SSDs behave and hopefully catch an issue before it is too late.   I had a lot of sudden & complete SSD failures (from a competitor) during the early days so my trust in the technology is not that great so I do understand your concerns. ... View more

You should give   this   article series a review as it contains a lot of good & interesting information about SSDs being pushed to their limits by running 24/7 over the course of several years.   It shows how Reallocated Blocks do not necessarily mean a failing drive.   Things may be a little different with the MX300 & MX500 series as they use TLC NAND, but in general I believe this still holds.   While with hard drives I would be concerned about a bad sector because most times it means you would get more bad sectors   which would actually interfere with performance until they were reallocated.    With SSDs this is a bit different and it is expected you will have some bad blocks from time to time, which is why they have some reserved blocks in place.   If you see a lot of bad blocks in a short period of time, then that is a cause of concern and I believe Crucial would most likey replace the drive (implied from a chat I had with Crucial tech support about a similar issue).   Keep an eye on the Unused Reserved Block Count to make sure you still have spare blocks.  When this count gets low, I would start getting concerned.   I have a bunch of MX300s with a few bad blocks each and they are still going fine.  With the MX300 series, make sure you are using the latest firmware (M0CR60) on the SSD as older versions did develop problems where a Sanitize/Secure Erase were necessary to correct issues.   As for your script, you may want it to trigger only when the Reallocated Block Count increases so you know when you receive new bad blocks, but it doesn't keep alerting you to the current ones.     The MX300 & MX500 use TLC NAND which is not as robust as the older MLC NAND SSDs.   TLC NAND is used in common consumer SSDs because the average end user will be reading from the drive more than writing to it.   If your customers are writing tons of data to the drive, then an MLC NAND SSD would probably be a better fit which the BX300 series are using I believe.    TLC NAND and newer are meant to bring out lager SSDs for a lower price, but doing so does have some unfortunate tradeoffs.   The "hostility" to returning the item is because they consider it to be working as intended which seems to be the case at the moment  This is common practice for most   companies.   I am just a regular Crucial customer like you and personally I wouldn't be concerned yet, but I would keep an eye on them.   Make sure the customers are backing up their data.   While this is always recommended, I think it even more imporatant with SSDs since data recovery may not be possible without professional services because of the way some SSDs fail. ... View more

I haven't found a list for the MX500 yet, so I've just been using the older list of attributes from here as the attributes I monitor are most likely the same.   I did see someone had already created a bug report with smartmontools to update the database for the MX500. ... View more

Are your chipset and SATA drivers up to date?   Are you using the Windows versions or the system/motherboard versions?   What size MX500 do you have?   Is the SATA controller the MX500 is connected to turned on in the BIOS/UEFI settings?   Are there other internal drives installed in the system?  If this is a secondary drive, does the partitioning type MBR/GPT match the boot drive's type of partiton?  I seem to recall someone had issues with Windows seeing the secondary drive when the partition types did not match. ... View more

If you make any changes to the SATA controller or protocols after the OS is installed the system usually won't boot. ... View more

Assuming the app is working, the SCSI error could be caused by drivers or perhaps a RAID controller or external drive controller.   The second error appears to be a software issue.  You should contact Crucial Support directly via online chat or e-mail to let them know about the issue and submit your system information and logs to them.   If you are trying to check the SMART attributes, you could install the command line smartmontools package or  GSmartControl if you prefer a GUI (at least until CSE issue is resolved).   These may not correctly show the attributes for the MX500 yet.  A lot of people like Crystal Disk Info. ... View more

Another post on these forums mentions a problem running CSE v3.55  with Win10 v1803 which results in a Java error.  The user said the ealier version of CSE v3.50 worked fine.   Try uninstalling, rebooting, and then reinstalling CSE.   Check that Java is up to date.  Perhaps make sure Windows is up to date.   If you have an earlier installer for CSE, I would try it after uninstalling CSE first.      Let us know if any of this solves your problem. ... View more

This sounds like a software issue whether with CSE or Windows itself or other third party system software.   Check any software which would be scanning your drives at boot.   Software designed to scan a hard drive for bad blocks or other issues may not work correctly when used on an SSD.   You may be able to find some information in Event Viewer or other system/application logs.   If you are installing a clean version of the OS, then it is advised to set the SATA protocol to AHCI mode so that you can apply firmware updates to the SSD.    When upgrading multiple items, I personally do them one at a time to make sure they appear stable.   It makes finding the problem a lot easier. ... View more

Is your BIOS/UEFI firmware up to date?   If you were using hardware encryption perhaps you need to remove/reset it.   What version of Windows are you using?   After installing Windows, did it boot into Windows the first time?   If you power down the system after the failure will it boot Windows?   What actually happens when you try to boot?  Does it POST, does it give "No bootable OS found", or does it drop you into the Windows Advanced Startup Menu?  Something else?   Can you bring up your BIOS/UEFI boot menu and see any UEFI boot options?  (Not inside the BIOS, but by pressing a key during POST to bring up a menu).   You could try booting to the Windows installer and select "Repair your Computer".  Go to the Advanced Troubleshooting and do a Startup Repair.   Go into the BIOS/UEFI settings and see if you there is a Windows UEFI boot option.   Some systems allow you to create a new entry manually.  Some also let you delete existing entries.   Since you are familiar with Linux, I would set your BIOS/UEFI settings to UEFI (disable legacy or mixed CSM support -- there may be more than one entry which has settings for this so check other menus).   Set SATA to AHCI protocol, and leave Secure Boot & TPM  disabled since some Linux distributions don't support it yet.   Then install Linux to your internally installed MX500 (Ubuntu or Linux Mint are probably safe options).   If this works after testing with multiple reboots, then it would seem to be a Windows issue.  If Linux does not boot, go into the BIOS/UEFI settings and manually add a UEFI entry for it.  When you search for the boot file, it will usually be on the first partition in a "grub" or "boot" folder (these may be inside of an EFI, or Ubuntu folder too).  Select the "grub_x64.efi" or "boot_x64.efi".   Some UEFI systems are very particular about the location of these boot files which is why it is sometimes necessary to manually create a custom UEFI boot menu entry.  Some systems will only boot if these files & folders are "boot/boot_x64.efi"  (or even boot.efi and you can rename them to this).    You could also try setting the system to legacy mode and reinstall Linux/Windows so it can boot using MBR and avoid UEFI booting issues at least for testing. ... View more

Make sure to reset all your motherboard's CPU & memory settings to defaults or Auto settings.   Incorrect custom settings could cause your memory to fail.   Is your BIOS/UEFI firmware up to date?  Only update it while using known good stable memory.     After unplugging the computer, press the power button, then wait a few minutes to let power dissipate from the motherboard.  If your motherboard has LEDs on it, make sure they are all dark before doing any work.   After intially testing Stick C and reinstalling Stick B, was Stick B in the same slot as before when it was working by itself (while waiting to recieve Stick C)?  If not, then it seems the other slot may have an issue.   Closely examine each memory slot to see if anything looks out of place or might be stuck in there.   Then I would blow some compressed air in each memory slot before installing the memory.   If possible tilt the system at an angle so if anything does come out of the slot it won't fall onto the motherboard or other components.   There is always a very small chance you have an issue with a slot or with another component which is causing the failures.   If so it can be challenging to figure it out.  I've been there several times myself.   Do you perhaps have an older known good stick of RAM you could use to test the suspect slot?   It's not a perfect test since the new larger RAM may be exposing an undetected existing condition with your motherboard.    If each memory slot works Ok individually, then perhaps you are exposing a flaw with the motherboard when multiple larger RAM sticks are used together. ... View more

What software did you use to clone your drive?   It seems the cloning software made the hidden partitions visible and kept the drive designations of both the hard drive & SSD from after the cloning process.   If you click on the C: & E: volumes do you see data on both or just one?   What happens if you create a file or folder on one of them, does it appear on the other?  Depending on what has happened, it may be possible to correct this issue without recloning it, but personally I would Sanitize/Secure Erase the SSD and clone the drive again using different settings or even different software since I would be worried about what else might have happened.    ... View more

 @djoser,   Using Linux run the following command on the Crucial firmware .iso file before using "dd" to burn it to the USB drive: isohybrid <path-to-firmware-updater>/MX200_MU05_Update.iso I believe the isohybrid command is part of the syslinux-utils package on Debian based distributions.   The isohybrid command makes the ISO image into a hybrid image which can be burned to either a CD or a USB drive.   This particular image only boots using MBR so you will likely need to enable legacy boot options in the BIOS/UEFI settings.    This procedure works for many of the Crucial firmware updaters. ... View more