you said a pad was off on the g clef side, yes that will make a note play when its not being played fer sure, very easy to fix unless you have a double tone chamber box, then ikts gonna be hard cuz you will have to remove all the keys to get at that if its a valve in the tone chamber, and if the drone is comming from the bass side, then real problem cuz the entire bass mecanism has to be removed to just see the bass pad valves, and oh yes all those bass botton vales-rods, they only fit in 1 place only, no excepetions, same as the g clef side as those keys also fit in only 1 location, if you its as you say and if you have to remove the key to get at the valve pad,, just make sure you tape a numbers on all of them if you have to remove them, as ikf you don,t you will have a jigsaw puzzle to figure out,and if its the bass side, have a pro acc repair man do that, but it does sound from what you said a g clef pad, if its not a double tone chamber box, you can put the valve - pad back on very easy with a lil bit of duco cement or reg acc bees wax.