2 x 1TB blacks WD1002FAEX made same day OK to swap PCB?

[Terablack]

I have two 1 TB black WD1002FAEX drives - with the same manufacturing date. One of the drives has issues ...

- Found in BIOS
- Still passes SMART but has high seek error count
- Instantly fails/powers down when MHDD cx seek/read test run
- Did well for the first 5 minutes using DDrescue but then slowed down dramatically, and further slowed to an unusable level after two days, with 90GB recovered about 40GB of that bad.
- The pattern above repeats itself although now only allowing me to recover 20-30 MB at a time.

At this point I'm guessing preamp issues but maybe not. If it is Preamp/heads I wouldn't be able to afford professional recovery but before I finally give up I thought I should ask the experts on this forum if it is at all worth swapping these same day PCBs or will the U12/adaptive info feature of these drives prevent that option (unless I swap the chip). I guess I'm wondering - if literally each eprom is customized for each drive as it is manufactured or is it batched?
Anyway;
thanking you all in advance

[Nick_CT]

Adaptive is unique to each drive. Chances that adaptives will work from another drive are extremely low. Maybe slightly better seeing they were made on the same day, but it doesn't really make a difference in this situation. Considering your description of the problem I would not say the PCB is a problem.

[pcimage]

Agree with Nick, PCB is not the issue here and will not help in any case.

[dmarques]

Someone experienced should diagnose it, because it's a bit unclear what's the problem.

[lcoughey]

PM Sent.

[poehere]

agree with Nick and PCimage this will not help you to swap this pcb out the problem is elsewhere sounds like you have imaging problems in this and you need a professional tool that can handle this to image the drive is this is the case. It also could be a weak heads but without seeing the HDD and just reading what you have written it is hard to say for sure if this is the case or not.