Stuart,
There's no 'Factory Reset' I'm afraid. I was just going to suggest checking that the Micro-SD card is in properly, but see Lee has beaten me to it. If Lee's suggestion doesn't cure the problem the rest of my post might, however, help point us to what is going on, so I have posted it anyway.
You say 'When powered up the red and green LEDs illuminate' - I take it you mean the two LEDs at the bottom left as you look at the end of the unit with the P3i antenna attached? Can you explain what each of the LEDs is doing - e.g. flashing or steady please.
Can you tell us how you are powering the Unit? Edit: See you've just done that - might be that the power block isn't supplying enough power - it MUST be able to supply at least 2 amps at 5 volts.
Can you connect your PilotAware to a monitor (or TV) with an HDMI lead and tell us what you see on the screen when you power it up, or take and post a photo(s).
Regards
Peter