One of my favorite jigs: The Oberheim SEM Tester
This box is a great way to troubleshoot and fix SEM's without having to take it in and out of its chassis.
The pegs on top that allow for it to rest easily and securely using the SEM's mounting holes.
Harnesses are provided with color-coded molex connectors that match the original chassis wiring.
The box also provides scope and meter outputs.