i hadn't run my show in a few days, i turned everything on, and one of the expresses wasn't turning the lights of the arch on, i hit the reset button on the express, and it all started working...
also, when i set everything up, i had 2 arches (from one express) stay steady on, i replaced the cat cable, and it starting working.
in that situation, when the lights were on, the led's for each channel were all lit as well.