Hi Pete
Here the 23 pin Amiga RGB port pins:
3 RED Analogue Red
4 GREEN Analogue Green
5 BLUE Analogue Blue
10 CSYNC Composite Sync
16 17 18 19 20 GND
-------EURO SCART:---------
2 Audio input Right
4 Audio ground
5 Blue ground
6 Audio input Left
7 Blue
8 Switching voltage
9 Green ground
11 Green
13 Red ground
14 Ground
15 Red
16 Blanking signal
17 Video input ground
20 Video input- Composit Sync
21 Screening or ground
Ciao
NOTE- i've intentionally omitted the "automatic Switch On" pins, due security pourpose. (sorry but i don't know your technical acquaintance level)
Switch your monitor/Tv set to "RGB IN" manually or, if you want ask me how :-)