I've installed the RAM, plugged in 2 PCI-E cables as per the quick start guide but then turning the PSU on does not power on the board.
OK. Please contact us through our website Live Support chat and we will help you get your board up and running.
I have tried 2 other boards with 2 different PSUs and none of them is able to power on.
Turns out I needed to plug a dummy plug/jumper into the 24 pin which wasn't mentioned anywhere.
Glad to hear you got the problem sorted out.
We actually included "ATX JUMPER PIN" adapters with all the ATX PSUs so our clients do not have to make their own jumpers. Unfortunately for the first few orders our shipping agent forgot to include those. Sorry for the inconvenience.

Are these 24 pin dummy plugs only needed for ATX style PSUs I assume? We'll be using a server PSU so I'm fairly sure that we won't need the dummy plugs...? I figured I'd ask to be sure while I'm waiting for other parts to arrive.

Well I just made my first purchase of a full setup from octominer. I am excited but see I have to wait till mid march for the next batch of motherboards before delivery. I also didn't realize there are additional shipping fees that I will have to pay the dhl guy upon delivery either.
We did not have to pay anything extra upon delivery here in the USA. I believe it all depends on the laws of your country in regards to imports, customs, duty fees etc...