Why do I hear tones playing with no keys depressed

 

What is happening inside a Hammond organ when a key is pressed?

When a tone continues to play, at least one of these contacts is not lifting back up. This usually means you need to start looking for a new organ. We can repair this to a degree, one key at a time, but how long will it last before another key starts doing the same thing? Usually not long. The keyboard is worn out from too many repetitions!