Roland JUNO-60 -1982    Weight=26 Lbs. Number manufactured = 30,000 MSR = $1495

Circuit Overview:
     A great 6 voice 1 DCO/voice analog with patch storage, and arpeggiator. Very similar to JUNO-6 with memory. Press '5' while pressing (6) or (7) to access those banks! The JUNO-106 adds MIDI instead of the DCB (Digital control bus) interface found on this unit, and also went to digital EG's. For this reason the 6 and 60 are a little more interesting to play with with arpeggiator I believe.

Service Tips:
      These machines use the same chips as found in the JUNO-106 modules but have real EG's. Just the discrete mounting though seems to take care of a lot of the problems that plague the 106's. But the battery is on panel board B on the right. This Li battery must be removed by either taking the board off or desoldering from below and removing I believe and shaking it out of there or something.
     WARNING! Do not attempt to 'clean' the switches on these units with contact cleaner etc.! It will cause the rubber contacts to swell and make them WORSE! To repair these contacts when they go foul, we've found that the very same ones used on the panasonic type key contacts will work on these. There is a testimonial below the bulletin on that here! But also beware of this issue...
     I worked on a unit that had an issue of only being able to access patch 11, 14, 17, 22-28, 32-38, 41-47, 52-58, 62-68, 71-77...! and often you can't save to them but some you can. If you hit a patch number other than those it returns to manual mode! manual mode (--) works just fine. I changed memory chips to no avail. I loaded factory sounds and it said it took them ok but no change in the behavior. It appears from the diagram that there is no logical reason for this in terms of button scanning. All buttons respond but not with particular things already in memory. (ie. the 1 button responds when you already have a 1, but not when you have a 7 as the bank number in memory already) BELIEVE IT OR NOT...the solution turned out to be a known issue. Power supply connector on the PS board...I torqued on it a bit and things started working. Possibly a cold pin because the solder looked ok. Also voltage had been close enough I thought (4.86V I was getting on the display board!). Wow. That's a peculiar manifestation. I'd counted segments to see if it was possibly PS related. Some with MORE segments lit were stable! That's one to think about. Roland had no idea why it was doing it but an old service bulletin notes that some early units had questionable interconnects on these that caused these types of problems.
     An issue of output distortion I see attributed to damaged mute transistors. Marc Marc says C45, C44, TR21, TR22, TR23 can all just be pulled if you don't mind some pop at turn on in JUNO 6 or 60. Verify equiv. parts in 106 schemo.