I got my MT-200s in the mail yesterday and had a chance to look them over.
One worked perfectly and came with an original Roland power brick. The other came in the original box with a Roland power brick and Roland midi cables (no paperwork but the serials on the box and unit match), but it would give "IMPROPER DISK" errors. I took it apart to clean the disk drive (a Chinon FZ-357) and after much scrubbing at the heads with a q-tip soaked in alcohol (there was visible gunk on them), it was still giving the error. I found an image of the drives jumper setup online (this floppy is apparently used in Amigas and other systems as well, but with varying jumper setups... rather uncommon for a 1.44MB floppy) and set it up to work on my test PC (a 440BX).
It booted a DOS 6.22 disk, but would only read disks some times, other times it would have a general failure. Eventually I realized that when inserting a disk (with the lid off the drive) I could still press the disk carriage down a tiny bit and it would always read reliably after I did this. It seemed that the mechanism for locking the disk in place was just gummed up because after doing this a dozen or so times, it freed up and I noticed that disks would snap into place much more tightly when inserted. Even the eject button felt tighter and less mushy after this, and now it was reading perfectly every time. I switched the drive's jumpers back to how they were before, put it back into the MT-200 and to my astonishment it works perfectly now! So I just got two fully working units for a very decent price, including original AC adapters, MIDI cables and one original box. Not bad. 😀
Hopefully some time soon I'll get a chance to run some tests to see if these units (both with 1.12 firmware) suffer from the same odd hanging note issues I experienced in certain situations with my older v1.00 MT-200.
Also, I'll attach the image I found for the Chinon FZ-357 jumpers. Presumably, everything marked in green (A) is for an Amiga setup, and everything marked in blue (I) is for an IBM compatible setup. I have one other Chinon FX-357 Rev. B that is a dark gray color and it doesn't seem to power up at all no matter what settings I use (in the MT-200 or a PC), but using the IBM jumper settings on the black drive from the MT-200 worked as expected.
I forgot to write it down, but I'm about 90% sure of the jumper settings for the drive in the MT-200 so I marked that in red (there were only two jumpers used).
Now for some blitting from the back buffer.