roland JC-120

[nosaj]

i have a Roland JC-120 where is the serial number usually located? Trying to figure out what schematic i should be using. It is using 2sd845 for outputs.
thanks
nosaj

[nosaj]

This one is different from others I have seen.
nosaj Roland JC-120H Jazz Chorus (84).pdf

[nosaj]

..

[g1]

i have a Roland JC-120 where is the serial number usually located?

Should be a metal plate on the rear panel next to the fuse holder.

[nosaj]

nothing on back panel just figured I'd ask if it was somewhere i wasn't seeing.

nosaj

[g1]

Does it have these other plates or screw holes where they may have been?

[nosaj]

Not that i can see.

[g1]

Should have a rear panel like this, with labelling for the jacks, etc. Is the rear panel missing?

[nosaj]

Yep.
nosaj

[g1]

Is the schematic you posted a good match?

[nosaj]

It seems there is no ch1 on it. The PCB number on the screened side is 701155200 doesn't match.
This one has a CH1 on the left then a CH2 with the effects distortion, chorus, vibrato I think.
There are 3 PCB's like the schematic I posted. The earlier service manual from 79 shows more PCB's than this one. But it does say on the foil side there may be other numbers so I gotta pull it an look.
The problem seems to be CH1 is ok Ch2 when turned up from zero makes the speakers work(going in and out0 horrid sound but not squeeling). When i check the foil side I check the caps.

nosaj

[g1]

The '82 schem. has ch.1 & 2, and 2SD845

[nosaj]

Much better alignment. Any chance you have a pic of the entire back so i know exactly what the jacks are for?
Thanks,
nosaj

[g1]

Much better alignment. Any chance you have a pic of the entire back so i know exactly what the jacks are for?
Thanks,
nosaj

howbowdah?

[nosaj]

Yep that works. Now a question. looking at the schematic if looks like each channel has its own speaker. is that right?
nosaj