Sonance powered sub quits working

I have a 150 watt sub that works for a few minutes than makes clicking sounds after that...Also sometimes it wont even come on as stand by light will stay red and not go green..when it was playing i switched the thx switch from adjustable to thx and it quit working..
Is this a power supply issue.
I was using speaker level inputs,not rca cable,,could that matter
clicking could be servo control?

perhaps the sub shuts off when there is no signal, might be a switch to keep always on.

i had a paradigm servo 15 that could act how you describe your sub, unless you mean that your sub stops working when there is an actual signal for it to reproduce.
It plays for few minutes than just stops,,when i hit the thx switch from normal to thx it will kill it too..when i turn on power switch after that it clicks