How to Fix My SSD Partition with "Unknown Format"

• Yes, it was encrypted from the very beginning probably because i had a password on the startup.
• Do you mean this command: " fsck_apfs -s -o -y /dev/rdisk3 " without -s like this "fsck_apfs -o -y /dev/rdisk3" ? If so below is the output. It gives me some paths to take.

Last login: Sun May  3 22:57:30 on ttys001
Murats-MacBook-Pro:~ muratsenocak$ fsck_apfs -o -y /dev/rdisk3
fsck_apfs: invalid option -- o
usage: fsck_apfs [-q | -n | -y] [-l] device
       -l            live fsck (lock down for verify-only)
       -q            quick check if the superblock and checkpoint superblock are valid.
       -y            always repair (answer "yes" to questions)
       -n            verify only (answer "no" to questions)
Murats-MacBook-Pro:~ muratsenocak$ 

Thanks Loner T. I hope I won't need their assistance because there is none in my area. Here is how my ssd looks in Terminal. The name of the disk is some fff-fffff-ffffff.

I really need disk1s2. Is there a way to reformat it, if somehow format has been changed or corrupted, or fix it without losing data?

It was the primary SSD in which the system was installed. Then I tried a couple of ways to reinstall the OS after the system crashed, but every time it failed for some reason. Then I bought a new SSD, and replaced the older one with it. I managed to install the OS on the new one after a few attempts. Then I connected the older SSD with sata cable to check if I was able to get my files back, but no luck. Next, I connected the old SSD instead of the optical drive that I detached years ago. The outcome is the same as the data cable. Here is the output of the command:

[Murats-MacBook-Pro:~ muratsenocak$ sudo dd if=/dev/rdisk1s2 count=5 2>/dev/null | hexdump -C
Password:
00000000  1e da 62 67 be c3 62 0d  01 00 00 00 00 00 00 00  |..bg..b.........|
00000010  5d 27 1c 00 00 00 00 00  01 00 00 80 00 00 00 00  |]'..............|
00000020  4e 58 53 42 00 10 00 00  0f ff 32 03 00 00 00 00  |NXSB......2.....|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000040  02 00 00 00 00 00 00 00  4d af 2e 16 23 c1 40 8d  |........M...#.@.|
00000050  97 d4 e1 43 d7 30 b2 d8  e7 8b 0a 00 00 00 00 00  |...C.0..........|
00000060  5e 27 1c 00 00 00 00 00  18 01 00 00 20 6c 00 00  |^'.......... l..|
00000070  d6 b8 01 00 00 00 00 00  5d 39 01 00 00 00 00 00  |........]9......|
00000080  04 01 00 00 42 3b 00 00  02 01 00 00 02 00 00 00  |....B;..........|
00000090  27 3b 00 00 1b 00 00 00  fb 8f 04 00 00 00 00 00  |';..............|
000000a0  12 4a 09 00 00 00 00 00  01 04 00 00 00 00 00 00  |.J..............|
000000b0  00 00 00 00 64 00 00 00  03 04 00 00 00 00 00 00  |....d...........|
000000c0  d8 a2 01 00 00 00 00 00  da a2 01 00 00 00 00 00  |................|
000000d0  20 41 02 00 00 00 00 00  00 00 00 00 00 00 00 00  | A..............|
000000e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
000003d0  00 00 00 00 00 00 00 00  8a f7 04 04 00 00 00 00  |................|
000003e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
000004f0  04 00 00 00 00 00 00 00  ab 89 e4 00 00 00 00 00  |................|
00000500  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000510  bf e7 68 00 00 00 00 00  01 00 00 00 00 00 00 00  |..h.............|
00000520  01 00 04 00 08 00 00 00  00 00 00 00 00 00 00 00  |................|
00000530  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00000a00
Murats-MacBook-Pro:~ muratsenocak$ 



Hey, Loner. Here is the terminal output you asked for. I hope this helps you to help me fix it.

Unfortunately I got this error, sir.

Last login: Sun May  3 17:41:43 on ttys002
Murats-MacBook-Pro:~ muratsenocak$ sudo gdisk /dev/disk0
Password:
GPT fdisk (gdisk) version 1.0.5

Problem opening /dev/disk0 for reading! Error is 1.
Murats-MacBook-Pro:~ muratsenocak$ 

Edit: The disk I should have tried was disk1 instead of disk 0. So it is my fault. I realized when i did "diskutil list". So below is the output. I'll reboot and come back.

Hi Loner. I rebooted. Macintosh SSD is back. But I cannot mount it. I get an error, below is the Terminal output of the error. By the way, given the fact that we are on the right track, may I ask if I can use this Macintosh SSD to boot the system and the one I am using right now as the storage disk? The operating system is now installed in this one that i am writing to here now, but i want to use the other.

Yes, you're right. I checked and the SSD is on disk3s1

Here is the result:

Last login: Sun May  3 17:58:53 on ttys001
Murats-MacBook-Pro:~ muratsenocak$ diskutil verifyDisk disk3
Unable to verify this whole disk: A GUID Partition Table (GPT) partitioning scheme 
is required (-69773)
Murats-MacBook-Pro:~ muratsenocak$ 

Last login: Sun May  3 19:55:58 on ttys000

Murats-MacBook-Pro:~ muratsenocak$ diskutil unmountDisk disk1

Unmount of disk1 failed: at least one volume could not be unmounted

Unmount was dissented by PID 0

Murats-MacBook-Pro:~ muratsenocak$ sudo fsck_apfs -s -o -y /dev/rdisk3

Password:

fsck_apfs: invalid option -- s

usage: fsck_apfs [-q | -n | -y] [-l] device

       -l            live fsck (lock down for verify-only)

       -q            quick check if the superblock and checkpoint superblock are valid.

       -y            always repair (answer "yes" to questions)

       -n            verify only (answer "no" to questions)

Murats-MacBook-Pro:~ muratsenocak$