My email is in my profile and I do offer the TIU Port tester kits for forum members, only to make them available for all here that still wanted them after GRJ made an initial batch and was then too busy to continue with them. I am not sure one of these would do much for you at this point and I think gunrunnerjohn would have suggested it if he had thought one would help in any way. After all he did the design of the TIU Port tester and knows much more about them (and TIUs) than I do.
After reading GRJ's and GGG's posts above I have to agree with them that someone with good expertise in DCS systems should visit your layout for some 'hands on' trouble shooting to help solve the problems you are having. GRJ and GGG are miles ahead of me in all of this stuff anyway, not sure I would know where to start.
