I updated my Internet Security software and now I have static through my speakers with no music on. What gives? Clean the connections? It's driving me nuts!
Kafka wrote a short story about a dog in a backyard who peed against a tree in the yard. At that same moment someone threw a bone over the fence. To the dog there was a connection. There was not. This may be the case with you, too. I would look for mechanical problems.
YMMV