Printed circuit boards are ... you would start a PCB design in a CAD package, but in 1969 the was incredibly manual. Everything was transcribed by hand from a paper schematic to transparent ...

No user-serviceable parts inside? Give me a break! The head unit is tough to get to, but the PCBs within the chassis use ...

Hopefully we can figure out what this circuit board does along the way ... Having a correct PCB design provides a way to check the schematic. Go to the PCB editor, update the PCB from schematics ...