Humminbird 998c Finder Buttons/Repair

[OneBlade]

My front Humminbird 998c graph may have gotten some water damage and now one or more of the buttons is not responding. I found some instructions online to take it apart and try and clean the buttons, but I'm doubtful it'll fix it and I won't break anything in the process.  Does anyone have an extra Humminbird they would be willing to sell?   I am looking for similar Hummingbird so that I can use the existing transducer already wired through my MinnKota trolling motor shaft.  I can look on ebay but figured I'd ask here.