I’ve got an F#6 and Ab6 on my keyboard that don’t make noise anymore. The G still works between them. Just wondering if a replacement part could be an option, unsure of what to purchase. Damage likely due to water if it makes a difference. Let me know if fixing this is possible. Thanks!
Without looking at it, it would be hard to say.
This keyboard uses rubber contact strips. I would start by looking into them. Could be that they need cleaning or replacement. (Syntaur sells replacements)