Hi again = Is it the 5-way con from/to the Data Link board (pcb2) that is the problem? If so, you can easily trace the cons from pcb2 to the main board - the 5-way con strip is there right in the centre (almost). If you look in the Service Manual 1-4 its there - if your eye-sight is good, you should have no problem! Let me have some feedback. = Regards Brian (Northumberland)
A bit more = Also look at 1-5. On page 1-4, you can see con 1 is joined to the anodes of both D4 and D5. Then if u look at 1-5 you will see that it goes to R2 and C4 on the main board - similarly with the other cons! This way you should see how all 5 cons go. Good luck.