I made the usual dullard move, plugged my laptop powersupply into the drive, over volted it. Realized it right away and disconnected, no smoke or anything, but apparently did some damage as the drive would not come up. I've removed it (it was already out of warranty) from the enclosure and tried the drive on an eSATA docking station, but it doesn't come up.
Haven't removed the logic board from the drive yet to inspect, guess that's next. Exposed surface looked ok, didn't see any indication of damage.
Got a PM in to Fzabkar.
Have been reading further, OEM encryption between the original MyBook eSATA/USB board and the drives logic board, even if you set no password?
Ugh. An ugly situation getting downright untenable.
Will get some detailed pics of the boards up tomorrow, at work at present.