Q: 2009 Xserve no boot after configuring LOM

Got a used 2009 Xserve 2 x 2.26 Quad that i just purchased. Fresh install of OS X 10.10. Running off internal SSD.

Currently no drives loaded in the bays.

Installed "Server" app, configured an working like a champ, running for 2-3 days.

Earlier today i configured LOM, the system remained to work as per normal as it has for the past couple days.

Had to reboot the machine before, after that it is absolutely useless, on startup it gets about 1/3 of the way along

the loading bar (on yosemite boot screen), and hangs there, have reset SMC, tried to reset NVRAM via the front buttons but

i cant tell if it was successful - see below.

Ive also tried to boot via a USB with Yosemite install on it - no go.

Disconnected and SSD and fitted HDD to a bay with a fresh working volume on it - no go.

Unsure about the function of Startup Method selection and operation though, I've selected the modes i want, then held the system identifier

button until the top row it lit up, let go of the button and then nothing happens, system doesn't turn off/restart in to that mode, it just appears to hang

after that selection. Is this right?