At 09:57 PM 1/17/03 +0000, Tim Myers wrote: I have the manual for that drive. My copy was published by processor tech, but it was just relabeled info from the original data sheets. It contains schematics for all the boards (something like 7) in the drive, and information on aligning and servicing the drive. it is quite a bit of information. I'm in the process of debugging a couple of helios drives, but the project has been stalled for a few months due to work demands and a lack of long-term debugging space. I have found a couple problems and the drives still doesn't work. The first problem was that a cap on one of the boards had developed a short, and when I turned power on, it would cause the voltage regulator for the +5 line to shut down, making further debugging hard. I ended up removing each board from the power supply until I figured out which one had a problem, then it was fairly easy to guess which component was the bad one (no marks, but the caps were the only parts going from power to ground. all other paths would have required at least two series parts to both develop shorts, which seemed unlikely). Another problem was a 74121 had an output go bad, making the part look like it was always triggered. This prevented the head from seeking to a different track (HOMEing to track 0 worked, though). One problem is that the schematics in the manual are for a different revision of the main board with all of the control logic. They are similar enough that the schematic helps, but different enough that you must double check everything. Please contact me off list and we can try and work out some sharing arrangement, or copies of specific sections. ----- Jim Battle == frustum(a)pacbell.net