Juno 106 Joystick not working

Synth Repair
1

Hi,

I have a juno 106 working perfectly except the DCO and VCF modultion functions on the small left panel. When i move the DCO knob, i can hear pitch changing and goes out of tune but the joystick itself will have NO effect at all when i move it. Same thing with VCF, i can hear filter changing when kove its knob but moving the joystick will not affect the cutoff value.

Any ideas on what can cause this ? I can do in depth testing and troubleshooting so open for any suggestions.

Thanks

2

First check the wiper of the bend pot (orange wire #20) to see if there is a varying voltage, I would guess that there is. If that’s OK then check for a varying voltage at the Bender CV out (#11, no color shown) to see if that has a varying voltage. If the first checks OK and the second is not the opamp ICs on the bender board are suspect.

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3

Great ! I’ll check and get back with fundings.

Thanks

4

Bender CV changes between 0 to 5.8.
Bender PoL either 0 or 4.7

Not sure whether or not these voltages are correct

I removed the joystic plastic and rotated the pot fully to both directions, it has NO effect whatsoever neither on the voice pitch nor filter even with both mod faders maxed 100%

Im tracing the lines and the circuitry is mot complicated. Started having doubt it might be one if the CPUs.

Any ideas ?

5

FIXED!!!

You won’t believe it. It was the bender board cable connecter on the modulation board. Had bad solder joints.

6

It’s old, broken solder joints are almost a given. I’m glad you’re back in business.

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