Hi,
My wife's Macbook Pro failed to boot, showing just a white screen. After some research it seems that it's caused by a disk error. I took her SSD drive out of the Mac, replaced it with a spare HDD, reinstalled the OS and the computer works fine, so it's not an issue with the computer itself it seems.

Her SSD I put into an external enclosure but any computer that I connect it to, complains that the drive needs to be initialized in order to be used.

I know as soon as I do that, I will essentially write a new index structure and all of the data will be lost and I will need a utility to recover it. However before I go down that route I would like to try to rebuild the directory and see if it helps.

I have Techtool Pro 8 installed on a Mac running Sierra, the drive I am trying to recover was from a Mac with El Capitan. I have the drive connected to my macbook in an external enclosure, Disk Utility sees the physical drive but no partitions etc for obvious reasons. Techtool doesn't see the drive when I go into volume repair, it's just offering me my internal drive. However if I go into the Techtool pro to go section, it can see the drive there.

So how do I go about trying to repair the catalogue on the drive, is there a way to do it without having to initialise it first?

Thanks!

Andrew

TechTool Protogo is simply seeing a device, which it would completely erase if it were going to make the device into a Protogo device.

I do not see how you are going to be able to repair the disk directory of a volume that is on a device with a damaged partition map ("complains that the drive needs to be initialized in order to be used") or one that is unreadable because of an electrical component failure within the SSD. It is not a good idea to attempt to rebuild the disk directory until you have been able to back up the data, which requires being able to mount the volume. If the data are crucial, and the attempt to repair the partition map described below fails, I suspect your only option would be the services of a data recovery firm, such as DriveSavers. Recovery from SSD drives is very complex, because the data gets written to locations chosen by wear-leveling. The data recovery firm has to have knowledge of how the firmware in the SSD works.

TechTool Pro 8 does not have the partition map tool. You can attempt to repair the partition map by launching Disk Utility, selecting the device (not a volume on it, if they were shown) and clicking the Repair Disk button, which should be a Repair Partition Map button when the device is selected. The screen capture below shows Disk Utility used to verify a partition map. I have repeated the text because the screen capture may be hard to read at some resolutions:

Verifying partition map for “HGST”
Checking prerequisites
Checking the partition list
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking the EFI system partition’s folder content
Checking all HFS data partition loader spaces
Checking booter partitions
Checking Core Storage Physical Volume partitions


The partition map appears to be OK