Sub-woofer not working

I have two Velodyn subwoofers hooked up to the 990. Both of they have stopped working all the sudden. At about the same time, or shortly thereafter, I am no longer able to access the video output to my T.V. to set-up the speakers. when I was able to and ran through the speaker set up it did not show any sub-woofers. I double checked hookup, power, etc. and that is fine. Help! Any Ideas? Thanks in advance. If software do you think installing the new version would do anything. I have not installed it.

You mention that the 990's setup menu indicated the sub was off? Is it possible that the 990 got reset to defaults?

Have you verified your connections to your TV. Usually an s-video connection is available for the OSD.