This post deserves a bump. I just installed a MX500 1TB SSD into a 2009 13" Macbook Pro (MacbookPro 7,1) and it wasn't being listed in Disk Utility. I then followed the instructions here and opened Terminal, ran the command diskutil list and saw that the SSD was /dev/disk0 (was able to confirm the exact drive based on the size of the drive listed). I then ran the command #diskutil eraseDisk JHFS+ "Macintosh HD" /dev/disk0 and after it completed the erase and format process, I close Terminal and reopened Disk Utility and the disk was listed. 1 item of note, in the command #diskutil eraseDisk JHFS+ "Macintosh HD" /dev/disk0, "Macintosh HD" can be replaced with any name you want to give the drive. If it has a space in it, then it needs quotes around it (and if no space, no quotes are needed).
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