I agree with siquack, check that the gold clips are secure. If they are, remove them and connect only to the top set of inputs, test, then try the lower set. If one set produces no output, there may be a bad connection inside.
On mine, the lower connection was broken inside. I didn't notice at first because audyssey configured the subwoofer compensate. But it didn't sound quite right and not very good with audyssey disabled/no eq. I thought it was odd that it set the the subwoofer crossover so high at 150Hz. I fixed the bad solder connection inside (suspect damage during shipping), audyssey set them to "full band" and subwoofer off. And now sounds amazing with audyssey on or off.
