Reply to "PS2 signal problem only affects one engine"

I might try disconnecting the spur feed on the terminal block and attaching it to the main track before the spur  switch at the switch point end.   Easy to try if you have a couple of alligator clips. It's either going to drag down  the dcs signal on the main track or perhaps fix your problem. . Ya never know.     Any spare tiu channels not in use?