No crank-non starter

[howey]

Howdy folks

Having bought a 2013 B7 2.0 tdi bluemotion on a cat n due to rear bumper damage it has been off road since purchasing due to waiting for log book.
Car was fine on test drive and was then delivered to me on recovery wagon.
I started it just the once no issues on my drive but didn't move it.
Today now it's taxed and Insured I got in it for the first drive.
It wouldn't start/crank so presumed the battery was flat. Fitted a known good one and still no joy. Noticed the cooling fans come on at what seems like full speed. Checked ECU for flooding but looked good and all wiring to visually looks good. Fuses look good in engine bay, need to check ones in the car.
Don't have any diagnostic kit to see if any codes or indeed any communications to engine ECU.

Anyone else had similar?

Cheers

Howey