Technical Papers
Greg Bogantz, a former top sound Engineer for RCA offers invaluable assistance in troubleshooting the 78 rpm mechanism. He wrote a complete description of the sequence of operations which is NOT included in the factory service manual.
It's 5 pages long and is highly detailed in describing the electrical and mechanical sequences in left side play, right side play, and both sides play.
"The Seeburg Select-O-Matic mechanism is a fantastic bit of mechanical engineering, elegant in its compactness. But there are LOTS of things going on in there and it took me a lot of time and experimentation to discern what all is happening inside the carriage as I worked to restore mine. I figured that most people wouldn't take the time to fully figure out this thing which typically results in ham-fisted "fixes" that don't work properly. I knew that I wouldn't likely remember all the details myself several years down the road, so I wrote up the sequence of operations for my own benefit. But I decided to also make it available to any interested owner.
Without a knowledge of how this beast works, it's pretty hard to figure it out by yourself - it's quite a bit more complicated than the reversing procedure in the 45rpm units."
-- Greg Bogantz