R80/RA81 diagnostic experience?

[resend - looks like original got lost this weekend] Hi, If anyone has diagnostic experience with an R80 or RA81, I'd like to pick your brain a little... If this is better done off line, email is fine. I suspect not everyone is interested on how to revive an R80 :-) (why *I* find it infinitely fascinating is something I'll never understand) I have an R80 which does not spin up or come ready: - All of the voltages are good (all the ones I checked anyway). - The drive belt had come off but I managed to get it back on - I can't seem to get it into diagnostic mode; the 8 leds' on the bottom pcb show 0101 0101 (hex 55). - When it powers up all of the external lights go on and stay on. - if I reset (click the switch ont the pcb to "R", the lights go out - if I then push the run/start it lights and after about 5 seconds the fault light comes on and run/start goes out. - if I push the fault light all lights go on and then the right most one stays on - push fault again and they all go out (I can then repeat the run/start sequence) I'm guessing the above behavior means the micro is operating, but then I set the rotaries to "FF" and hit 'enter' (i.e. put the toggle to 'E') the led's don't change at all. The manual says they should flash and change as a I enter diag mode. I wanted to use diag more to force a spin up but no joy. Does the unit have to be connected to a controller to go into diag mode? I have an RB730 which this connects to. Connecting is does not seem to really change it's behavior. -brad