Made sure all diodes were the same in column 2- no change
Did the wire from connector to pin rows test and the only faults to show up were;
When the"I" in KISS was lit-30million glowed
When the 2nd "S" in KISS was lit-30million glowed,rescue and movie madness all glowed.
So, possibly row  4????? That's assuming you have the column and row sheet for CFTBL.
To throw a spanner in the works, doing the above test in all lamps test didn't show all the issues in single lamp test.
Also have replaced u10 and u11. I looked at schematics and  I do understand what you mentioned.
Appreciate your help.