Trouble with RL02.

I'm trying to get my RL02 working with my 8/A. Thanks Tim R. for lending me a cable and terminator! After finding a cold solder joint at the 8.2 MHz oscillator on the RL8A, I thought I had it licked... the master clock would start and stop if I pressed the oscillator's case. Now there is a steady 4.100136 MHz clock at the ribbon cable connector to the logic board inside the drive. The power supply voltages on the board are all within spec. The problem is that not only does the Fault light still stay on, the ready light (that illuminates the "Unit 0" plug) is also on. According to the manuals this is not supposed to be possible since the ready light only comes on when track 0 has been found, and the heads are still locked home :( ??? The Load button has a very dim bulb, near end of life, but it does light after the slow 15-second disk rotation. Pushing the Load button does nothing (disk does not spin, Fault and Ready still lit). Examination of the state machine lines shows that it is in state 0 (Load Cart) but the input to it (DL5 ERR STATE COMD L) is also asserted. When turning the spindle by hand (from the access port underneath the drive, with a cartridge in place) I can get a signal of at most 0.2 volt p-p. This doesn't produce any pulses from pin 1 of the LM393 amplifier. If I ground the "Raw Sec Pls Return" then I can get a very noisy pulse train. When it's "inching" in startup mode it is maybe 10 mv p-p which is way below the spec in the manual and nothing comes out of the amp. Is this sensor hall-effect or is it just a coil? DEC went out of their way to run 5 volts to it, so I assume it's a transistorized unit? More importantly, anyone got a spare? :) thanks Charles