I have a two subwoofer hook up which has been working fine for the last 6 months. Suddenly my LFE signal is cutting out on one SW and nonexistent on another. When I run the test signal I get no output.

Hmmm.... My first thought is to check your cables at both the 990 and the two subs - a loose connection or two could easily create what you are describing. If all the connections are secure, the amps are both turned on, and you still can't get a test tone from the subwoofer channel, it might be worthwhile to get Outlaw in the loop (either on the phone or their support site ).

Thank Gonk. I checked the cables and they seem fine. The 990 is hooked to a 7700 with balanced cables. I will call Outlaw tomorrow. Thanks.

Sounds like a plan. In the meanwhile, I suppose it wouldn't hurt to make sure nothing has gotten changed in the 990's setup (sub is still set to "on" and speaker bass management settings are right). The fact that you were getting some output from at least one sub makes me doubt that the sub output simply got turned off, but it's at least a quick and easy thing to rule out.