Drawing a complete blank on this one from all the usual manual sites and
search engines. Anyone got the schematics for a Roland JC-50? Numbers on the
PCB are "AP110" and "141-110"

It dates, I believe, from around 1978, and is not the same as others in the
JC (Jazz Chorus) series such as the JC60 or JC120. I particularly need the
bit that shows the wiring of the "Vib-Off-Chorus switch. Someone has
replaced it, and it doesn't work. I am pretty sure that it has been wired
wrongly, but with eight tags and five wires, there's a lot of potential
combinations ... The vibrato oscillator is running as you can see it on a
'scope, and the speed and depth controls work. It's just not modulating the
signal. As to whether the chorus circuitry is working, is anyone's guess.

TIA

Arfa