I'm having a problem with one of my Leviton DDS-6000-15 dimmer packs. I'm unable to control any lights plugged into it via dmx. It's not an addressing issue- I was able to get other DDS-6000s to work just fine. I'm able to control fixtures after it in the data chain, but on this pack the dmx indicator light doesn't come on. For some reason this pack just doesn't recognize dmx signal. Lights plugged into the dimmer just run at full and don't respond to dmx, even after toggling dip switch #8- which is the lamp test. There doesn't appear to be anything obviously broken, corroded or disconnected inside. Anyone else run into a similar issue?