Most commonly when we have that problem we just need to visit the
circuit board and find that the
circuit breakers are flipped.
Are your houselights just with the rest of your lights on dimmers?
When ours are, we find they generally don't work because:
* Soft patching we've forgotten.
* They're unplugged up by the lamps.
* Someone's messed with the
dimmer pack settings. (ie. not addressed correctly,
circuit breakers flipped,
* Every single light
bulb has blown

* We have a scene parked and forget to change from
park to subs
etc.
* We've gone into edit mode and something has gone drastically wrong.
I'm sorry I can't help much.