Had to take my HU back to Halfords to be sent off for repair today. It's been having intermittent issues just randomly turning off and not turning back on, so I moved all the wiring about behind the HU, and tidied it all behind the glove box. All was OK until Thursday.
Went for a drive, put the facia on, and nothing, HU won't even power on. Checked all the wiring (as there is quite a bit with it having to connect into the CAN-BUS for steering wheel controls) and that is all OK.
Took it back to Halfords as it's less than 12 months old, and the bloke from the ICE department said he was having the exact same issues with his HU....which was the same as mine. Should be back within 7 days, but could take upto 28