Hi, new guy here!
I got my cube on Monday and the setup was a breeze thanks to this awesome guide

First thing I did was to open the case and checked each board heatsink, and as you guys said, some of them needed to be tightened.
After everything was ready I connected the Cube to the modular Seasonic X650(
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151088) I got specifically for it, only to hear an immediate click after turning it on. FAIL#1

Luckily there was a Corsair TX 750
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139021 in my gaming pc.
Removed it from my pc case, connected to the cube, and it worked! The seasonic works great on my PC and I see the consumption is about 10% less.
Kept the default pool and entered all my info. It was hashing at 36GH/s with 90% efficiency, and was consumming 355 Watts (80 Plus Bronze crap efficiency).
FAIL#2
I left it on overnight, and when I checked it in the morning it was off

Kill-A-Watt, said it was on for 9 hours.
When I turned it on again, it shut itself off after a minute. I kept trying and now it just turns on for a few seconds, or doesn't turn on at all.
Also tried with the other 2 PCIe cables, and also had 2x (2 molex to 1 PCIe) adapters, with the same results.
If I disconnect the Cube, the PSU starts, so maybe the cube did something to the 12v rails or related capacitors.
I also tried each of the boards separately, and even without any, but the PSU didn't kicked in, so maybe it did killed it.
Right now, I'm stucked waiting for a Corsair RM 750
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139055&Tpk=corsair%20rm%20750. I will probably get it delivered to my country in 10 days, I don't know if I should buy a Thermaltake, because it might or might not last the 10 days... if it even turns on (and the store that sells it sucks with returns)
If the new PSU also fails, I will try adapting capacitors to the cables. Hopefully it doesn't require any soldering.