Look at the switch on the drop target too. Sometimes the metal armature will be a little loose and sloppy, causing it to get hung up out of it's normal position and not allowing the drop target to fall. Could be the little tabs the armature clips to on the switch are worn or broken, which will give it too much play. Sounds like this is your problem with the drop target sometimes not going down. When it happened to mine, no matter how hard I hit the drop target, it would not go down. Would work sometimes, then get stuck and not go down. Replaced the switch, problem solved.