I had all 4 on a 800 watt PSU & they ran fine,just had 1 that zombied & they were hooked to 1-4pin molex cable with 4 molex connectors......only for about 30 minutes till I moved them to a dedicated PC.
They all had lights on then & after I moved them.
Here's some info I found:
http://en.wikipedia.org/wiki/Molex_connectorScroll down to the "disk drive" connector section,"11 amps @12volts=132 watts per",per molex or per cable.I think per cable,so 2 on each cable with a HDD or DVD rom each should be fine.
We are assuming 40 watts or so per board (with no OC'in),so 80+ watts per cable should be within the limits.
The 2 did not lose the green lights till many hours(6-8 hours)after I had them running on the other PC.
Harddrives are 10 watts or so,DVD rom is about 10-15(not burning,25+ when burning a DVD/CD).
So......40x2=80+15=95 watts per 4pin molex cable.........in range I think..............
Either way,its strange..................
Edit:Just hooked a PSU up with "high tech" jumper wire to turn it on & still no green light.
I 100% agree with your power assessment of the individual molex cable. I am only running two boards and a fan per each molex connecter. I always worry about overloading molex connectors, and if I'm doing a great deal of daisy chaining, I always like to check with a multimeter to make sure I am not going over spec. Two blades per a molex cable seems to be the most I would attempt.
Hopefully Barntech will release a list of surface mount components to check for failures. This would make troubleshooting a no led situation much quicker (i.e. - check these fuses, its a known problem). I guess you could start by verifying the surface mount fuses, as I would suspect those first for failures.