Usually there is no sound from the sub. If I unplug the RCA cable, switch it off for 10 seconds, then on again, then plug and unplug the RCA cable rapidly ~10 times the sound comes back. Sometimes this doesn't work, forcing me to start again from power cycle. Also, it makes a loud popping noise when I switch off the sub now. Bought the soldering gear for repair, what part do I need to switch out?

Audio Players & Recorders - Wharfedale - PowerCube PC-12 Subwoofer