MFM HDD + XT-type controller: I/O errors throughout drive (10pts)?

Hello. This one's obviously for the older posters among us... many of us weren't born when this technology was current. Anyway, I have a Samsung XT clone (8MHZ NEC V20,) and it has both a Seagate ST-225 and a WDC 1002A-WK1 controller card. The storage subsystem is aftermarket, was already installed when I received the PC, and has never been tested in the five years I've had the machine sitting around. The cabling looks fine, I've reseated the controller, and double-checked the drive model. I've not verified jumpers, but have a printout for all BIOS revs; will try and figure out which mine is, but I'd assume the jumpers would have been set right by the prior owner.

Now for the problem:

Spinrite II reports a bad drive controller when I try to run it on the drive, but doesn't offer up much more info. Disk Manager completes a low level format, and makes light clicking noises as it does so (not unlike a 5 1/4 floppy stepper). But, when DM goes to verify, it finds that none of the sectors are readable, and gives a seek I/O error. The drive takes an easy thirty+ seconds to check each head of a cylinder, and as it tests, makes a whirring sound, then a tone that falls in pitch. It repeats this three or four second long sound-pattern at least five or six times per head. Disk manager diagnostics reports the drive's seek mechanism works, and while running the test, it produces some almost musical notes towards the end, which may or may not be normal for an ST-225. Random read testing fails, with similar I/O errors/sounds to those above.

Solution:

Well, is anyone familiar with the iconic ST-225? These old drives sounded distinctive, I hear, and perhaps the sounds it makes can tell whether it's controller failure/jumpering, drive failure, or perhaps, both.