On my newly acquired Roland Juno 106, I discovered I had a dead key (E) on the lowest octave. I researched and found out how to open, remove, and clean the carbon contacts ( upper and lower ) for the dead key. When put back into order I still had the dead key problem. So I then figured the carbon contact located on the Silicon rubber had to be wiped out. So I looked around on the Internet and found a gentleman who was selling just what I needed. They were “stick on” Carbon Contacts for Silicon Rubber with Dead Keys. They were not tested on a Juno 106, but for $25 bucks a sheet I decided to pick some up for a possible fix or future use. I attached two photos of what I received in the mail last week.
I opened up the Roland Juno 106 and once again took out the dead lower E key. I gently placed a new Carbon Contact from the sheet onto the Rubber Silicon. You need to be careful when doing this as they do fly off the tweezers quite easily. It happened to me once, but luckily I found it. Then I closed up the Juno 106 and gave it a try. It didn’t work…laugh. Seriously it didn’t work at all. This means that the Carbon Contact either didn’t work ( unlikely, I’ll explain later ) or that I have now isolated the problem to the actual contact on the board below the keys. I now most likely will have to remove all of the keys, and trace the patch to the dead key to try and find a break in the connection. For now, I can live with the dead key as I don’t use it much and I can always midi up a controller with aftertouch and everything else that the Juno 106 doesn’t have.
I did however as a test tried putting a Carbon Contact on a key that already worked and that worked fine. The Carbon Contact from the new sheet completely covered the old contact. I am assuming that if the Carbon Contact itself didn’t work, then it would block the original causing the key to become weak or even fail. Thus I am willing to bet that if and when an actual Silicon Rubber contact fails, these new replacement Contacts should work just fine.
The Gentleman whom I purchased these from at http://sounddoctorin.com/synthtec/parts/key.htm is a great guy and very sincere. He was extremely helpful and his website has quite a bit of useful information on Synth repair. He also has replacement parts for sale. I highly recommend trying these new Carbon Contact Replacements for your dead keys provided you only have a problem with the Silicon Rubber part. If you have an issue on the board itself, then you’ll need to isolate the problem and perhaps do a bit of soldering to reconnect the dead key. I have read about this being done on the Roland Juno 106 and other synthesizers so it shouldn’t be too difficult.
If you are actually missing Roland Juno 106 keys and need replacements for physical broken keys, I have seen many on Ebay. However, they are often sold one at a time, so it could be expensive if you need many keys. As always, you should weight the option of buying a second used Juno 106 for spare parts instead of selectively buying parts. Good Luck!