I have now accepted defeat ever restoring the sat nav to my unit and am now accepting "The Man from Germany " was correct in his diagnosis that it is more than a laser/mech problem.
After kindly being given yet another NCDC 2013 by NickW,with a proven history of working , to have a play with I removed the entire headunit and screen from my car.I then fitted both the headunit and paired screen provided by Nick to establish it worked albeit a Black/White system.It accepted the disc and loaded everything as it should and provided sat nav along with radio and cd functions.
Thinking atleast we have a working mech and laser I thenn stripped it all back out and took it apart and removed laser and mech and fitted that all back into my own NCDC unit.Had high hopes when I fitted it all back into the car,but that didn't last long.
Same old problem as before of disc being ejected after a few seconds and no audible noise of any spinning disc or action.Only thing that does happen is when disc is drawn in the illumination of the disc slot goes out and after trying several attempts screen advises disc needs cleaning...obviously it cannot read the disc.
If anybody has any other suggestions I am happy to listen as at present I have 2 nav mechs and lasers along with 2 cd units 1 of which is paired to a monochrome screen..big box of bits and back to square 1