Q1: What is the pinout for the nine pin d-connector on the back of the A4 laptop ? (For PSU replacement).

A1: Oddly, the information is in the 'portable guide':

Pin   Signal    Meaning
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1     UMAIN     charger system supply
2     0V
3     OE        charger o/p enable
4     0V
5     CRSEL1    battery charger current select
6     UBAT      charger battery supply
7     CRSEL2    battery charger current select
8     IBAT      current feedback signal
9     0V

Note that the pins are numbered with 1 at the top-left and 9 at the
bottom-right, when looking at the 'solder-tag-side' inside the A4.