Update all fixed. Replaced with my old TZ Optus. Dunno if my new sets are compatible or not. The main difference I can see is the pcb has both ke and ac instead of k/a and c/a on the respective opto. It may have been a bad set, but I think I may have had a similar problem when troubleshooting my tz???

Anyway checked the manual and I did have everything wired right etc. The switch does stuff all except acknowledge you made it half way up the ramp and so will award a hit on a Martian etc whereas making the second switch awards a missile. Otherwise you'd rarely notice as you usually associate making the complete ramp shot with the associated awards.

Thanks guys for your assistance.