Well this is a new fault. Went to start a print this morning and as I had removed the glass bed for cleaning I ran the auto-levelling routine, or at least I tried to run it.
Screen came up with the following error

After a power cycle next to nothing works. Trying to move the axis does not work, running the aux level, axis does not move. Running the auto level the nozzle temperature increases quickly to 110 or 111, but the display then 'freezes' and the temperature does not update any more, axis does not move.
I've tried re-flashing the firmware, still the same. It's only a couple of months old and not had a particularly hard life so far.
Any 'Creality' admins out there can advise what I need to do to get my unit running again?