Use the Sony AV Adapter SCPH-1160 for this mod:


 PSX pin | cable color | SCART pin | description
-------------------------------------------------
 12      | green       | 11        | RGB Green
 11      | red         | 15        | RGB Red 
 10      | purple      |  8        | +5V (to power up LCD monitor)
  9      | blue        |  7        | RGB Blue
  8      | pink        | 17+18     | Video Ground
  7      | white       | --        | --
  6      | yellow      | 20        | Comp.Sync (only for NTSC LCD monitor)
  5      | light green | 20        | Comp.Sync (only for PAL LCD monitor)
  4      | orange      |  6        | Audio Left
  3      | grey        |  4        | Audio Ground
  2      | brown       |  2        | Audio Right
  1      | black       |  4        | Audio Ground