Chosen Solution
Hi. I bought an SSD drive for my old MacBook Pro to speed it up, but there is a problem with it. I prepared a bootable USB with OS-X El Capitan and put the new drive into my MacBook. So I was trying to erase disk through disk utility, but there was a problem like ‘couldn’t save to the last block of the device’. I formatted it through another laptop to HFS+ and tried to install system, but OS-X installer didn’t recognize my disk. Now disk utility cannot open, it just stays on ‘reading disks’ and nothing happens, but it’s okay when i disconnect disk, then disk utility starts fine. When I try to format disk through Terminal I get error ‘couldn’t unmount disk’. I’ve read a post on a forum and someone was sure that problem is faulty SATA cable, so I bought a new one and replaced it, didn’t help. The SSD is KINGSTON A400 120 GB. Thanks for help in advance.
Well, you fell into a common problem which I’ve seen over and over again! Your system offers a SATA II (3.0 Gb/s) interface. The Kingston A400 SSD spec sheet claims it’s a dual speed, supporting either SATA II (3.0 Gb/s) or SATA III (6.0 Gb/s) systems Kingston A400 SSD But for some reason its acting as if its a fixed SATA III installed into a SATA II system! At this point either the SSD is defective or this is a copy of a Kingston SSD (a cheaper SSD labeled as Kingston!) FYI: There was a flood of fakes showing up last couple of years, as an example: How to identify fake Kingston v300 SSD. I would return it and maybe look at getting a better drive like a Samsung 860 EVO which I know works! Update (12/13/2019) The only thIng I can think of is finding a friend with a Mac running El Capitan (the highest OS your system supports) using a StarTech 2.5" SATA to USB adapter cable to connect your SSD to that other system. Using Disk Utility and the OS installer they have prep your drive. Don’t forget you need to back date the system which is running the OS installer and your system so its within the certificate date window.
While this in more about the newer macOS’s the issue is the same here If you’ve got an old macOS install image, it will probably stop working today as Apple forgot to update the certificates in the newer OS’s. In your case, Apple stopped updating its certificates which is why we need to back date the system to Dec 2015!
