Problems updating a 13" Mid-2012 Macbook Pro from an HDD to SSD

You may have been caught by the "clone, don't copy" issue, or possibly the sequence in which the ops are done. I did the conversion successfully several years ago and used an OWC "kit" that included a simple USB transfer case. I also changed the drive cable at the same time out of an abundance of caution.

1) I put the new SSD in the OWC transfer case and connected it to my Macbook Pro 13.

2) I opened Disk Utility from the old internal HDD and formatted the SSD as APFS, required for SSDs with 10.13 or higher.

3) I'd previously downloaded Carbon Copy Cloner (CCC) to the old HDD, and used it to CLONE the entire contents of the HDD to the SSD, still in the external case.

4) CCC will prompt you to recreate the important recovery partition. Make it so.

5) With the new SSD still in the external, I opened the Startup Disk SysPref to confirm the new drive was bootable.

Only then did I remove the old HDD and install the new SSD and its cable in the Macbook Pro. Booted first try, although first boot will be a bit slow.

Now, before doing anything else, do System Information > SATA/SATA Express to see the new drive. If "TRIM Support" shows "Yes," your work is done.

If not, use the Terminal command in this article to enable TRIMForce on the SSD:

https://eshop.macsales.com/blog/31619-how-to-execute-trimforce-command-with-your-owc-ssd/

I found that, if not done, the drive will slow later to old HDD rates or worse.

After enabling TRIM, restart in safe mode and give safe mode time to do its housekeeping required after enabling TRIM. 30-60 minutes depending on how full the drive.

Anyway, that sequence gave "first time good" on my Macbook Pro 2012 13-inch and I still use it today.

tweav270 wrote:

I have an older (mid-2012) 13" Macbook Pro that I would like to pass on to my kids as I upgraded to an M1 Macbook Pro 2 years ago. I am trying to replace the original HDD with a 500GB Crucial SSD (it is an MX500). After installing the SSD on the laptop I initially tried to install Linux and almost got through the process but the bootloader didn't want to recognize the hard drive after the installation media was removed so I removed the hard drive and used the recovery system on startup to make a clone of my old HDD (the internal drive at that point). This failed so I opted to install a fresh copy of Catalina onto the hard drive through the recovery system (the SSD was externally connected via a dock). This succeeded (yay!) and it immediately booted into the newly installed operating system. I then re-installed the new SSD into the laptop and started it up and the bootloader doesn't want to boot from the drive (all I get is a grey circle with a slash through it that blinks randomly and sometimes I get the folder with a question mark). If I have the old HDD docked and connected as an external drive it will boot from that and I can see the SSD as an internal drive through Disk Utility and even in my Boot Manager as a selectable option but it won't actually boot from there (though it happily boots from my old HDD when it is the internal drive). I have cleared the NVRAM/PRAM and this doesn't seem to help.

I have read that these 13" Intels sometimes have issues with the SATA cable but wouldn't that cause read issues when my HDD is the internal drive as well?

Any thoughts would be appreciated. Thank you!

Did you replace the SATA cable at the same time as your new SSD...

recommended on the "mid-2012 13" Macbook Pro" a known point of failure ie generic faults in printed circuit traces.

ref: SATA replacement 13"MBP mid 2012

https://eshop.macsales.com/item/Apple/8211480/%20%2013%22%20MacBook%20Pro%20SATA

SSD are more demanding then you HDD, it is a classic issue. Replace the SATA cable and compare your results.

tweav270 wrote:

Well, a new SATA cable and 30 minutes of work later, the Macbook Pro boots up just fine and runs like a dream. Thank you both for your help!

Good computing tweav270— sounds like an upvote to me !