thanks nino but i'm still having hassles with it  now it seems to work intermitintly and then the opto seems to get stuck on and the score keeps climbing,the board i re-flowed was the reciever and now if i wiggle the opposite board the tranceiver it seems to set it off again and get it working once more,what would be the chances of the two stuffing up at the same time,i can only conclude i must have disturbed it,i also have a post that is only half in the playfield as it had been bodged up with wood putty but that has fallen out so now it leans like the tower of pizza see picture,it moves everytime the ball hits it, so i am not sure if thats causing the fault please note photo the opto in the photo is the reciever and is the one i reflowed  also i am unsure of the perameters of opto's ie:do they need to be aligned perfectly to work and how fragile they are if they can be put out of alignment by a bump ect there is also another set of optos just down from these two and i dont even know what they do they dont seem to do anything when the ball passes between them,any advice would be appreciated,i'm planning on spending sat night taking the under playfield ramp off so i can get to the other opto boards to remove for reflowing.
ben