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.

Is it about recovering data or restoring the drive to working order?

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Data recovery Poland (RAID, HDD, SSD) - https://hex-serwis.pl

I already recovered all the data from the other drive in the RAID1 array, so data recovery is no longer the goal.

What I'm trying to do now is restore this drive to working order and, more importantly, understand what actually happened to it.

What puzzles me is that throughout all the testing—including multiple full-disk writes, reads, surface scans, and SMART self-tests—the drive never developed a single bad or reallocated sector. The only symptom was progressively slower reads, eventually degrading into a drive-wide slow-read condition.

I already recovered all the data from the other drive in the RAID1 array, so data recovery is no longer the goal.

What I'm trying to do now is restore this drive to working order and, more importantly, understand what actually happened to it.

What puzzles me is that throughout all the testing—including multiple full-disk writes, reads, surface scans, and SMART self-tests—the drive never developed a single bad or reallocated sector. The only symptom was progressively slower reads, eventually degrading into a drive-wide slow-read condition.

The behavior described indicates a problem with the ReloLista (Module 32).
This damage can be caused by spontaneous overflow, but is more often the result of head and/or surface degradation.
The absence of errors may simply not have been registered by SMART yet.

The LDR loading error may be due to access to the SA not being blocked at the ROM level.
https://blog.acelab.eu.com/pc-3000-hdd- ... oblem.html

Can you list which SA modules backup by WD Marvel?

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Data recovery Poland (RAID, HDD, SSD) - https://hex-serwis.pl

Hi Lukas,

First of all, thank you very much for taking the time to help me.

Unfortunately, I don't have access to a PC-3000. The cost of asking a specialist to recover or repair this drive with PC-3000 is actually higher than buying another WD4003FZEX, so I'm trying to solve the problem using WD Marvel.

The backup contains many SA modules, so instead of listing them in the post, I've attached the complete module list as a file.

Thank you again for your help. I really appreciate it.