Paradigm PS1000 Speaker "stopping power amp thump" Questions

...power came back on , the subwoofer immediately started making loud thumping noises. I had to unplug it or turn it off to stop it. It also doesn't seem to be working, Anything I can do or just buy ...

...power off. Also, it only thumps once I turn up the gain, otherwise there is no sound coming from the sub. I am pretty sure its not my receiver. It must be the sub. Is my sub destroyed? thanks for the ...

...power supply or possibly the amp circuit that has gone. If there are electronic guys in your area, they should be able to sort it out relatively easily. Get a quote first, make sure it is in ...

...power and plug it in again the humming disappears and doesn't come back until I play loudly with the subwoofer again. Could you please advise? I have tried changing the subwoofer signal cable without ...