Hi, I'm not too much into synths, but very used to repair electronics in generel. I have a Juno 106 in for repair, and it makes a slight noise on channel 5 only. I found out which channel it was by entering the service mode. The noise is quite unstable, sometimes popping and scratching, sometimes it's almost gone. I have also noticed that the same channel sounds a tiny bit more lowpass filtered than the other channels. I tapped and heated a bit on the analog circuit board to the left where the oscillators are. It sounds like a dry solder join, but it is completely insensitive to mechanical stress or heat. I also jerked the cables and plugs with no effect. I read on the web that the black vertically mounted VCF/VCA hybrid circuits sometimes fail. Is that a likely cause? Anyone experienced something similar? BTW, I saw someone needed a service manual for the same synth, I found it here. http://www.hinzen.de/midi/juno-106/manual/juno-serv.pdf -- Ulrik Smed Aarhus, Denmark
Ulrik Smed wrote: > I read on the web that the black > vertically mounted VCF/VCA hybrid circuits sometimes fail. Now I swapped the hybrids in channel 5 and 6, and now the noise is on channel 6. So it is the hybrid that is defective. -- Ulrik Smed Aarhus, Denmark
On Sunday 14 May 2006 07:03 a poster that claims to be Ulrik Smed wrote: > Ulrik Smed wrote: >> I read on the web that the black >> vertically mounted VCF/VCA hybrid circuits sometimes fail. > > Now I swapped the hybrids in channel 5 and 6, and now the noise is on > channel 6. So it is the hybrid that is defective. > Those 80017A chips can be found on eBay, usually for about $60 USD. http://search.ebay.com/JUNO-106_W0Q...106QQsojsZ1QQsspagenameZSTRKQ3aMEFSRCHQ3aSRCH Those VCF/VCA chips have failed on me several times through the years on each of my JUNO-106's. (I have three of them.) -- Respectfully, Ru Drisi heartsofmusic.com Music is the shorthand of emotion. - Leo Tolstoy
Ru Drisi wrote: > On Sunday 14 May 2006 07:03 a poster that claims to be Ulrik Smed > wrote: > >> Now I swapped the hybrids in channel 5 and 6, and now the noise is on >> channel 6. So it is the hybrid that is defective. >> > > Those 80017A chips can be found on eBay, usually for about $60 USD. > http://search.ebay.com/JUNO-106_W0Q...106QQsojsZ1QQsspagenameZSTRKQ3aMEFSRCHQ3aSRCH > Those VCF/VCA chips have failed on me several times through the years > on each of my JUNO-106's. (I have three of them.) Thanks for that tip! I called a local Roland service center today, and they haven't had those chips for a long time. They knew the problem, and actually suggested to find one on the net too. -- Ulrik Smed Aarhus, Denmark
On Tuesday 16 May 2006 14:59 a poster that claims to be Ulrik Smed wrote: > Ru Drisi wrote: >> On Sunday 14 May 2006 07:03 a poster that claims to be Ulrik Smed >> wrote: >> >>> Now I swapped the hybrids in channel 5 and 6, and now the noise is on >>> channel 6. So it is the hybrid that is defective. >>> >> >> Those 80017A chips can be found on eBay, usually for about $60 USD. >> http://search.ebay.com/JUNO-106_W0Q...106QQsojsZ1QQsspagenameZSTRKQ3aMEFSRCHQ3aSRCH >> Those VCF/VCA chips have failed on me several times through the years >> on each of my JUNO-106's. (I have three of them.) > > Thanks for that tip! I called a local Roland service center today, > and they haven't had those chips for a long time. They knew the problem, > and actually suggested to find one on the net too. > There are also workarounds. I think Isaw one published once. I expect that if you ever replace a chip with a workaround PC board, you'll probably have to do all six so you don't have mismatched timbre issues. As you may have noticed from the service manual they suggested something similar about 80017A versus 800170 chips. Good luck. -- Respectfully, Ru Drisi heartsofmusic.com Music is the shorthand of emotion. - Leo Tolstoy
