I have just the tower speakers from a sony sava 500 theater system. The other day the right speaker with the control interface make "thump" noise and stopped working. It happened once before then, but the sound came back after a day. This time the sound refuses to come back. When I turn on the speakers I hear a clicking noise, presumably the amp?, however neither speaker will produce any sound. The fan also isn't working, however I don't if that was a consequence of whatever happened. Any idea what component of the speaker is malfunctioning?

Edit: I've already tried different output ports and changing the red-white audio cable.