The owner of Machine Design died about 5 years ago and most of the knowledge about the autoblender went with him. I was helping him some and have some info/knowledge about the units.
The earlier models were a more simple unit that was easier to maintain. He then started building a more technical unit that was somewhat easier to operate but harder to fix if there were problems. If you can email me a pic to
tcollins@ec.rr.com, I can tell you which model you have. There is an owners manual that came with the unit which will pretty much only tell you how to turn the unit on/off and do the mix setting. No service info is available(the owner kept it all in his head). Since there is no liability coverage on the units, you probably won't find anyone to give you info(I only know of 2 people, of which I am one, with any service knowledge).
Once I see which unit you have, I may have an owners manual I can send you a copy of(it's only a few pages).