[Brand New TT Toughpower Grand 1050W won't power on!]

I have installed my TT Toughpower Grand 1050W in the chassis, attached only the mobo cable and used the included jumper adapter to connect the green and black cables (actually there'll all black but you probably know what I mean). After plugging the PSU into the mains, I turn the switch on and nothing happens - no fan, no hum.

 

As this is a brand new power supply, I'd like to think that I'm doing something wrong rather than the PSU being DOA.

 

Any advice (other than returning the PSU, which is a pain as I bought it via Amazon...)?

 

Simon