Roland RD-700SX – One key is too loud (fixed!)
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• Model & revision/OS:
Roland RD-700SX
• Symptoms (what changed, when):
One key has been too loud for years (never serviced until now)
• Tests already done (voltages, parts replaced)::
Hey everyone. This is actually a recounting of my “repair experience, hopefully for someone else’s benefit. I finally decided to try to fix my F5 key that is WAY too sensitive and louder than the rest. After some Google/Youtube searching, I found a Syntaur blog talking about this issue and decided to try cleaning the sensor rubber “boot”. Disassembly was uneventful, and I got the keyboard bed turned over, found the problem rubber boot (a short 4-sensor one) and removed it.
Upon CLOSE inspection, everything looked in order, with the F5 looking identical to the rest of the working keys. But I went ahead and cleaned the carbon contacts with alcohol and a lint-free cloth, as well as the metal contacts on the circuit board. Reassembled enough to test and the key was still faulty, possibly worse than before. I had the lowest volume/velocity available on that key (as before), but the rest of the sensor range seemed to be peaking at FF.
So as I was about to post to this forum for help, it occurred to me to try moving that sensor/boot to another location as a troubleshooting technique. Turns out most of the notes on that circuit board were using parts of a 12-sensor boot, except for the top 4 notes of the keyboard which were also 4-sensor. So I switched that one with the F5 one and VOILA! Everything was fine again. Even the highest A, which happened to be the note that used the sensor formally on the F5, was working fine. Weird, but what a relief! Repair complete!
Hope that helps someone.