Someone Somewhere said:
Check display etc. plugged in properly? You don't get BIOS/POST?
Does sound dead, though I can't imagine how.
Yep, it was plugged in properly, I tried 2 different HDMI cables on the TV plus an old VGA cable. Then tested it on my PC monitor using HDMI ... and nothing.
I get no output from the TV / PC at all, so as far as I can tell no bios / post but without a display I can't really tell. The motherboard doesn't have a speaker so I won't get any beeps it might make during the POST.
I also checked the power supply, it's just a 19v plugpack and using a multimeter confirmed it was putting out about 19.3v
I'm still baffled how it died. I didn't even change the WOL setting in the BIOS, it was already set on. I simply used it to power on the machine a couple of times via the XBMC remote on my phone.