-/No/Off button not working

[sys700]

The -/No/Off button on my EIII is not working. I tried a little Caig Deoxit spray, but it still didn't work. So I tried swapping it with another button from the sequencer section but the -/No/Off button still doesn't work. The only thing I can figure is there must be a broken trace or some component has gone bad. Anyone ever experience this issue before? I can use the data slider for most things, but I can't disable voices because I can't turn them "Off". I'm sure there's other things I won't be able to turn off or say no to. This is an issue because my EIII also has an issue with the left/right outputs not sounding as I cycle through certain mono sample sets. Any help would be much appreciated!

[midipuppies]

Whenever I hear of problems like this, I am always suspicious of the 60 pin ribbon cable that goes from the card cage to the front panel.
I have 3 EIII keyboards and all of them have had an issue with that damn cable. Certain buttons will not work, certain LEDS will not work sometimes.
Have a look at it to see if it is in any way chafed or rubbed. Wiggle it carefully and see if the problem changes to another button or LED or not. Even if nothing changes, I would still not rule it out as being a potential problem.

[sys700]

Decided to try to fix it this morning. I disassembled the board attached to the top with all the buttons on it. One of the traces had a wire previously added. I made sure it was soldered properly, but still no luck. I decided to run duplicate wires along the traces in case there was a hidden cracked trace. In order to do this without melting the buttons I had to desolder 4 buttons with direct connections to the -/On/Off button. Then I cut pieces of wire to mimic the traces and soldered them in place. Then replaced all the buttons and soldered them back in place. Still no luck. :-( Then I had an idea...I wonder if the next button downline from the -/On/Off button is actually working? It was the transpose button. Sure enough, it wasn't working either. So I ran a trace from the Transpose button to the next button downstream in the Analog Filter area. Bingo! The -/On/Off button started working, along with the Transpose button.

Now I still have an issue with my jack board. At least I'm pretty sure there's a cracked trace, a bad component or resistor pack that is causing most mono samples to not play properly in stereo across every voice.  Anyone have any ideas?