Hello Brian,
Was the DX box plugged in during the last three weeks of non-use or was it unplugged? (for the last 3 weeks it was not connected to any power source)
Did you try swapping the DX boxes? IE connecting the normally daisy chained box directly to the console and then daisy chaining the normally directly linked box instead? (Yes I also tried that, swapd every cable connected in the system 2 times and connected it straight to the table with cables that I tested on my other DX that has no problems, unfortunately it would still not switch on)
Did you try swapping power cords and outlets? (Yes many different ones and tested ones)
Did you try swapping cables? (same answer here as above)
Did you happen to upgrade firmware in the console recently, or use the non-functional DX box with another SQ console that might have had a different firmware version on it? (The boxes will automatically download the correct firmware to run, but the boxes need to be connected directly to the console for this to happen). (Good questions, but unfortunately its a complete set for a couple of years now and never switched out for other stage boxes or another sq, and currently its running at V1.5.1 for at least a year now without any problems)
