Replacing a Catalina HD with a new ssd

Hi,

First, is your MBP's drive replaceable?

If it is, you'll need a cable adapter or enclosure so you can connect the external SSD to the MBP. Download Carbon Copy Cloner, connect the SSD to your MBP, select Macintosh HD (or whatever you named it on your Desktop; you don't have to worry about choosing between the System and Data volume) as the source drive and the SSD as the Destination, click Start and wait for it to finish. There may be a step or question or two to make it bootable and format it as APFS, I don't recall exactly. I recommend reading the following: https://bombich.com/kb/ccc6/frequently-asked-questions-about-ccc-and-macos-catalina. When it's finished, boot to it to test it out (hold down the Option key while booting and select it) before installing it in your MBP.

I can also recommend Carbon Copy Cloner as well. Been using it for years to make a clone of bootable macOS drives. You definitely want to properly erase the new SSD by using Disk Utility to erase the whole physical SSD as GUID partition and APFS (top option). You may need to click "View" within Disk Utility and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. The physical SSD will either be identified by the make & model of the drive or by the USB chipset of the USB adapter, dock, enclosure.

Another option is to perform a clean install of macOS on the new SSD, then during first boot Setup Assistant will give you an option to migrate from another computer or drive. This option may not properly transfer some licenses for some proprietary apps like MS Office. CCC may keep the license of some proprietary apps intact.

WPG Mark wrote:

My mbp kept shutting down and restarting as it was doing the cloning process

That's not normal and may have corrupted the cloning process. What was going on that may have caused your MBP to shut down & restart repeatedly?

I'd erase & reformat the SSD then try using CCC again. In Disk Utility make sure you select View > Show All Devices and erase the entire SSD, not just the container. The SSD must be formatted as APFS. Then run CCC again.

Make sure your MBP is connected to power and in System Preferences > Energy Saver set "Turn display off" to Never and make sure "Prevent computer from sleeping" is checked. You can undo these settings after you have completed the cloning process.

Check the health of the hard drive using DriveDx. Post the complete text report here using the "Additional Text" icon which looks like a piece of paper. A failing hard drive could easily cause issues during the cloning process. I highly recommend you copy off any important data from the SSD while you have access to the data since the data on the original hard drive may be permanently lost if the hard drive is failing. If the hard drive is failing, then the more you use the drive the worse the failure will become where even an expensive professional data recovery service will be unable to access the data.

If the hard drive is healthy and the SSD (cloned from the HD) boots & works fine externally, but fails when installed internally, then either the internal hard drive SATA Cable is bad (really common with the MBPro 13" mid-2012), or the SSD is not compatible with the laptop.

WPG Mark wrote:

I had bought 8GB Kit (2x4GB) DDR3 1600MHz SODIMM RAM, Royemai PC3-12800 2Rx8 1.5V CL11 204-pin Notebook Laptop RAM Memory Module from Amazon, and was able to return it. Any recommendations on what RAM would work or what the issues is?

Macs are very picky about the RAM they use so it is best to only use memory from Crucial or OWC. Even then make sure to only order the exact part numbers listed when using the tools on their respective websites to identify your computer & memory. If you just purchase memory based on speed (or the other limited public specs listed by Apple), then most likely even the Crucial memory will have problems as well. RAM has a lot more technical specifications than are typically listed by the computer manufacturers and even on the memory product page. These other specifications are just as important for compatibility plus some of the non-brand name memory (even some brand name low end memory) are just poorly made. Crucial even lists "Mac Compatible" on their product page for the exact parts which are compatible with Macs and even has "Mac Compatible" printed on the plastic packaging containing the memory. Our organization has been using Crucial memory since they began selling to the public almost 20 years ago and we very seldom get a defective module (3 or 4 out of thousands) and never had any compatibility issues.

https://www.crucial.com/

https://eshop.macsales.com

I'm not saying other good quality name brands of memory won't work. I'm saying many manufacturers don't specifically list Mac compatibility or make it as easy as Crucial or OWC to identify the correct compatible memory. Definitely stay away from the non-name brands since they may not have the same quality of supporting circuitry on the module even if they use name brand memory chips.

It may depend on exactly what model MacBook Pro you have.

You're welcome.