Weird Roland Juno-106 Issue (Any ideas?)

[Pollux]

Demo Video :

https://www.youtube.com/watch?v=Y3pVQMAxx0s

I bought a juno-106 for a good price. After being powered on for an hour, I noticed some voices started to "crack".

I ran thru the testing procedure (http://www.analoguerenaissance.com/JU...), and voices 2 and 3 failed the VCF Test. On voices 2 & 3, the cutoff was about half of the other-voices, so I thought It was the famous bad juno chips.

So I ordered all brand new Analoge Renassaince Wavegenerator and VCF chips, and installed them. In poly mode, everything sounded perfect to my ears, I could hold down chords forever, pound them over and over, and it sounded relatively the same (read, good) each time. But....when I ran thru the testing procedure again the aforementioned issue(s) STILL happened.

So I took It to a Roland Service Center and had them tune the voice chips, thinking it was a tuning issue. They called me, and said the problem still persisted, and said It was likely a very low level issue such as the software, or ram (but didn't know forsure). Now, when I hold down a key for 2+ seconds, It sounds like vibrato gets applied ( and notice the LFO Is off!). This wasnt happening before though.

Anyone know what the issue could be? Possibly the cpu board ( I wasss thinking about getting a Kiwi-106 CPU board anyways....)

[DES]

I watched the video...weird stuff for sure. I couldn't tell for certain, but when the pitch seems to drop, is it always the same key? If so, it could be something in the keyboard decoder...possible dirt/foreign objects in the key bed, bad diodes or connections. Try playing it with an external midi controller. That should help isolate the keyboard section at least.

Check all the connections...pull them then re-seat them. Also look for any caps that might be failing....might be swollen or leaking (old Korg gear is notorious for this). Variable controls like potentiometers, joysticks, etc can go bad too or have junk on the contacts.

Usually when a cpu section goes, the board is dead. What I hear sounds like a control/modifier input to the cpu is acting up. Of course if its all on the same board, replacing it may fix the problem...

[Pollux]

DES -- Thank you for your reply man :] I need a closer look around at the DAC, CPU, RAM, and Multiplexer Chips from what It sounds like.