Roland Jazz Chorus no chorus

I have a JC 60 thats working except for the chorus , vibes working . It seems to be a pretty old one , serial no 430887 3 board model , cant find a schematic .Any ideas what the problem is . Im a bit lost on solid state . Ive worked on plenty of valve amps , I dont have a scope but I can trace a signal
 

PRR

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Joined 2003
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JC-60 is a half of a JC-120. -120 schematics are readily findable. They seem to list by year, not serial or board-count. The first couple years used JFETs to pre-amp the guitar signal. 1984 used chip opamps. The switching for the chorus function is moderately complex and very eye-painfully drawn. Good luck. (While I love the JC, if the choir died, I'd get a chorus pedal.)

Roland's site lists all these beasts so they may be proud of them. Ask, they may know what plan you need.
 
Hey PRR, do you know what they use in the preamps in the new reissues of the JC40s and JC120s? I’ve been looking for any info about that and it doesn’t seem to get much attention anywhere, that I can find anyway. Makes me figure it’s nothing special… if they used JFETs or something cool they’d surely use that as a selling point one would think…

Old thread I know, just thought I’d try in case you see it :)