Hi, yes dash lights up, glow plugs do their stuff,
goes out o.k comes up turn the key for final turn to engage starter, nothing, no starter solenoid being thrown forward no dying battery noises, no engine crank. Dash lights go out and don't come back on until soft boot carried out( until then nothing electrical works even if left for sometime, battery disconnected etc), noise from centre consul like a strangled duck which goes away if the side lights are turned on or ignition key turned thro one click.
Terminals the cleanest i have ever seen, threaded adaptors to terminal posts worked from side to side to get a good contact. Battery removed and underneath was a flat profile fairly wide piece of metal which i think is earth strap which is secure and shows no signs of corrosion.
this leads me to think that there may be a connection problem at Bii loose plug or corrosion to terminal which overwhelms the Bii and drops everything electrical and if this were dead then the screen would go dead like a voltage drop but i can't find the Bii to check it, regards