Now if your getting green light but no eject thats usually down to either a rip in the cable or more likely the Fuse for cd has blown, check with multimeter, as for black screen, could be down to a few things, check B-I for bridge or loss of conectivity etc, probably find whatever is causing your black screen also caused the fuse to blow.
Diagrams have been posted by charlie_ps2 in a thread somewhere just search for fuses
V4 Pal 30004 Messiah
V5 Pal 30003R Messiah
V7 Pal 39003 SmartChip
V9 Pal 50003 Silver(had to have a shiny one) Matrix