Guess what! I disconnected the orange pair and now Line 1 is working fine. It looks like fault is somewhere on the orange pair (house wiring?) but why did that cause fault on the rest of the 3 pairs?
Oh well; I am no longer going to play with it any more. It was an interesting experience and good exercise in sharpening my diagnostics skills Let us leave it at that.
Oh well; I am no longer going to play with it any more. It was an interesting experience and good exercise in sharpening my diagnostics skills Let us leave it at that.