Why does my amp turn on but no sound?
If the amp drives that just fine, then you have a problem with your speakers or wiring. If you still don't get any sound, then you could have a faulty amplifier, although you'll want to check that it isn't in “subordinate” mode and that you don't have conflicting filters before you condemn the unit.
Why my subwoofers are getting no sound?
Ensure the subwoofer is connected to the MIX or SUB output on the stereo system or TV. Ensure the power cord of the subwoofer is connected to a working AC outlet. ... IMPORTANT: Certain sound field settings may disable the subwoofer. Trying a different sound field may resolve the issue.