Reading Data from Fusion Drive

Yes, you can actually remove the internal HDD and slip it into an external SATA to USB3 (USB2 is very slow so please try to get USB3) enclosure and actually boot off it on another WORKING mac (that is at least 2011 or newer). If you place it in the working mac, hold the ALT/OPTION button and power up, it will show you the connected drives with the external HDD looking like a “yellow” drive icon.

You want to do this because you can then log in as yourself with all the permissions intact and then back up the contents. If you try to access the drive from another working mac, you have to enable permissions/etc which is beyond the scope of my abilities to tutor you on. This is especially true when you want to open certain mac specific apps to gain access to your old passwords because you never remember then (like me).

Also, your SSD should have more frequently accessed files so it migth have recent copies of frequently used content (videos, images, notes). You might want to check that as well.