Just a quick question about the 20" Aluminium Cinema Display - Does it need to be connected to a Mac via the DVI/Display port to actually come on eg. Green power light? I've just received one I bought on eBay and I can't get it to turn on with all the power supply hooked up. As I don't have the right DVI adapter I can't tell if this is the cause of the problem. Naturally i'm worried i've been sold a broken display. Any info would be really useful, Thanks.