Thanks for your patience Jijo.
So in privileged mode I simply type: "device# erase startup-config unit-id 2,5,7-8,10"
The instructions give 2,5,7-8,10 as an example only. Are these the correct numbers for an ICX 7150 C12 switch? Sorry if I'm new to CLI.
Will this effectively be a factory reset? Right now the switch doesn't seem to put out any power, and there are no flicking green lights when I plug in the ethernet cable (and I have tried another cable) and so something is seriously wrong with it. I just want to start again.