June 19, 2026
I’ve started to noticed this the last few times I wanted to use my BK-7m… the menu settings were not being chosen when turning the rotary encoder knob Encoder Rotary Switch was not able to select the options in the menu that I wanted… I’d swing it around, a move that usually sent it from one end of the list of chouces to the other… instead it *might* move up or down one item on the list, sometimes it did not move. I was dreading this… it means that the Encorder Rotary Switch was having issues.
Encoder Knob
Encoder Rotary Switch
This can happen under one of two circumstances… either the knob built up some gunk and the connection insides were not happening or the insides were simply wearing out and not making a good contact. I was fervently hoping for the latter.
I bring up the BK-7m on my table upstairs, open up the bottom, spot where the encoder knob is and see the circuit board where the rotary encoder switch is located. I pull off the knob from the outside, inside I remove the connector that is attached to it and remove the bolt holding the switch to the case.
I rotate it in my fingers and it feels smooth. Pulling out my WD 40 Specialty Electrical Contact Cleaner, I start spraying it in every tiny opening and the top all the while rotating the switch back and forth vigorously. At one point I suddenly feel the ratcheting movement inside get more obvious/evident. I give her a few more hard blasts with the cleaner, wipe it down outside and let it air dry for a few minutes.
Once done, I return the piece to where it was, and close things up and bring it down to the basement and place it on my desk. There are three possibilities that can happen now… the thing dies a nasty death in a puff of smoke, it still won’t work and requires a new encoder rotary switch… or it works.
I plug it in and turn it on… no smoke, and the screen comes to life normally. I turn the encoder and… IT WORKS. Whew!!! Talk about being dramatic! So now it works 100% again, but I wonder how long before it happens again?
I do know this… if it does happen and I ever need to replace the encoder switch there is one place that I can get it… at THIS website.
https://syntaur.com/parts/roland/bk-7m
Too much drama today, I’m going back to playing some accordion!!
Addendum: June 20, 2028
Thanks to some good info from a fellow accordionist on the forum, I sought out the piece on Amazon. Now as of the time I created this post, it still works well, but I was told that this is likely going to be a temporary fix, so I searched on Amazon for “uxcell 360 Degree Rotary Encoder Code Switch Digital Potentiometer EC11 5 Pins 15mm Shaft” and found a kit of 2 switches for about $11. I’ve since receieved them and they sit in a secure drawer ready for use if needed.