RL02 Tracking

Hi everyone I've posted a few times over the years about RL02 drives and my difficulty getting them working (no luck so far!). I've spent the past few days working on one of them and have made some progress. The status currently is that the heads will load, and the ready lamp flashes as the heads wobble back and forth very slightly, trying to lock onto the outer servo guard band. Probing TP2 of the read/write module, I can see the S1 servo burst flash (roughly in time with the ready lamp). If I disconnect power to the servo motor, I can manually move the head onto the outer guard band (less than a mm away) and monitoring the position signal (TP15 on the drive logic module) shows this to be close to 0. So, I'm very confused. I've worked through chapter 3 multiple times... - voltage checks - all good - sector transducer output check - all good - sector pulse timing check - all good - read signal amplitude check and adjustment - all good - positioner radial alignment - required some tweeking but is good now - head alignment - looks good to me - spindle runout check - a little noisy but within spec - position signal gain check - looked ok - tachometer ac noise pickup check - this one didnt look so good Supposedly if the main drive motor is bad it will emit noise and cause the tachometer (just a coil of wire on the head carriage) to produce spikes. Mine does look quite noisy but I'm not sure what's causing it. I would expect that if it was picking up noise, I'd be able to detect this with my oscilloscope probe by putting it close to the motor, but I can't. Any ideas? Also, thanks to pjustice on irc who suggested checking the spindle grounding button. Mine is very worn out but I've been able to apply some pressure to it from the under side which reduces the resistance of the spindle to ground, from 400 ohm to 0 ohm. This didn't make the situation any better though. Still, the situation over all is much better now than it was last time I looked at the drive (over two years ago now I think). Previously the heads would attempt to load and then the fault lamp would come on immediately. At least now it's trying to lock onto a track. I have the same results with two cartridges (which is all I have!). If anyone has any ideas I'd love to hear them! Aaron (Sorry, as usual, about the footer appended by my university.) This message and any attachment are intended solely for the addressee and may contain confidential information. If you have received this message in error, please contact the sender and delete the email and attachment. Any views or opinions expressed by the author of this email do not necessarily reflect the views of the University of Nottingham. Email communications with the University of Nottingham may be monitored where permitted by law.