Roland stopped making the replacement Ics some years ago. However there is a guy over in Europe who is making a good quality reproduction. So if you have an old juno laying around that you thought was beyond hope due to bad voice IC’s you thought wrong.
I have installed this new part in several Juno keyboards to date, they work great and even after several years i have yet to have had one fail.
Here is a link to the part: http://www.analoguerenaissance.com/D80017A/
I do not recommend attempting this one yourself as the traces on those old boards are pretty touchy and they can be destroyed pretty easily.
Randy Morgan ….. Owner & head technician at All Service Musical Electronics Repair