Neo Bike - gears, fans and display not working

Hi All,
I recently had my Neo Bike (original, not plus) replaced with a refurbished one this week - this was due to a gnarly noise from the pedals/flywheel.
It all worked really well yesterday.....but this morning, I logged on to my usual zwift morning session and everything connected up beautifully.
However, the display on the neo bike flashed up briefly then went blank, the fans stopped working and I stopped being able to change gears. Highly unhelpful!
I tried power cycling the device and checked the cable was plugged in to the back of the head/display unit, but nothing worked - it looks like there was a backlight on the display, but no data.
Anyone had a similar experience or any advice?
Thanks in advance!