apple Lisa2. Any advice on non-working floppy drives?

Hi Guys, Anyone on the list have experience with the Apple Lisa? I'm having fun playing with three broken Lisa's (1 Lisa 2/10 and 2 Lisa 2s) I aquired about a month ago. The aim is eventually to get the Lisa 2/10 and one Lisa 2 going eventually. The Lisa 2/10 comes up with a disk controller error during the I/O board check. I don't have an I/O board I can swap out I've shelved that one until I can get one of the other Lisa 2s going. After a systematic check of what is and what is not faulty in the three Lisas, I've now got one of the Lisa 2s to the point where it asks for a disk. And here's the problem. I can't get any of my sony Lisa 400k 3.5 drives (all three of them) to show any sign of life? You can see the little LEDs come on inside but nothing mechanical moves at all? I have 2 LisaLite controller boards, but swapping these around makes no difference. I find it hard to believe that all three drives have exactly the same problem or even that both LisaLite boards have the same fault (although it's always possible I guess?). The only thing not swapped is the main cable going from the backboard connector to the Lisa Light controller? However the connecting ends look ok with no sign of missing or damaged pins? Before I dive into some deeper diagnostics, I just wonder if I'm missing something obvious here? Has anyone else had this problem or can suggest what might be wrong? Do these Lisalight controllers often fail (say by someone plugging them in backwards...Apple II drive controllers can certainly be killed this way) and how likely do you think it is I might have two faulty ones? (or three faulty drives for that matter). Any comments most appreciated. Terry Stewart (Tez)