Hello everyone,
I would appreciate any help or suggestions regarding the following issue.
**Drive:** WD4003FZEX-00Z4SA0 (WD Black 4TB)

I had two identical WD4003FZEX drives running in a RAID1 array. One of them started dropping out of the array because of extremely slow reads. However, the drive had no reallocated sectors, pending sectors, or obvious bad sectors.
I performed a full surface write using Victoria in DDD mode. After that, I noticed strange regions of approximately 150 MB where read operations would slow down significantly (1–5 seconds per block), while writes completed successfully.
Short self-tests consistently reported errors, but each time at different LBAs, generally beyond the middle of the disk. After running a Long Self-Test, the drive degraded into a severe slow-read condition across the entire capacity (typically 1–2 MB/s), still without any bad sectors being reported.
SMART only showed occasional **"MultiZone Error Read"** entries.

What happened next
Unfortunately, I made things much worse myself.
Using WD Marvel, I reset SMART, the translator, and several service area modules. Before doing so, I created a restore point and assumed it would allow me to recover the original state if necessary.
However, after the reset, the drive no longer starts correctly because the SA modules are missing.

Current situation
* The drive does not initialize properly.
* Restoring the WD Marvel backup fails with the error:
**"Overlay not found"**.
* Direct track writing from a donor does not work.
* Writing DIR also fails with error **3745** (no additional explanation).
* Any operation involving SA modules returns:
**"Module not present in DIR"**.
* ROM can still be read and written successfully.

Inside the backup folder, and also in HDDGuru backups from similar drives, I can only find overlay **11**, and it is present.
If overlay 11 exists, what exactly is WD Marvel looking for when it reports **"Overlay not found"** during restore?
Has anyone encountered this situation on a WD4003FZEX family drive, or knows what component is still missing that prevents the backup from being restored?
Any advice would be greatly appreciated.