PCB or SATA connector failure across multiple drives

The other day I rebooted my FreeNAS machine and when it came back online six of my eight drives were missing. Testing the drives in an external enclosure shows they didn't even power on.

The odds of six drives failing at exactly the same time with no warnings from FreeNAS seemed extremely unlikely so I took the PCB from one of the working drives and transferred it to the broken drives one by one and they all powered on (but are unusable due to the BIOS mismatch between the PCB and disks).

Logically, I would assume that this just means either a broken PCB or SATA connector. I tested each of the "broken" PCBs with a multimeter against a working PCB and didn't see any differences.

Replacement PCBs are easy to acquire but these particular drives (WD 10TB Reds) do not have a BIOS chip, so I can't transfer it from the old PCB to the new one.

Anyone with more knowledge have any ideas about this or how I can salvage my data? I don't really care about the drives themselves, I'd just like as much data back as possible.