I've just acquired a box of STFMs and am having great fun with them.
One has a problem. Its an old TOS 1.02, 360kb floppy model. The onboard drive light and the keyboard drive light stays on when the drive has stopped. The drive works ok, but when it stops and the light goes off, it then spends a few seconds returning to full glow again. The drive stays stopped. The problem is that the external floppy drive most times can't be accessed. The external light comes on - but the internal drive operates. A message that the B drive is not accessible appears (occasionally the B drive does operate). Disconnecting the internal drive still leaves the keyboard drive light on - and the external drive inaccessible.
The board has a RAM upgrade. A card on top of the MMU chip, a memory card, and a Video Shifter chip. I removed the MMU card and memory card, just leaving the Video Shifter chip in place. The system boots ok - but the floppy problem is still the same.
Dud board? (I can't see any obvious damage to the board)
Just out of intellectual interest - does anyone know what the problem might be?