I wish it were that easy. No I definitely have the cable plugged into Ext Sw. it’s right below the Fxn Sw jack. Nothing plugged into Exp Pdl. I also tried 2 different TRS cables and I checked continuity on the tip, ring and sleeve on y cable and got good connections and no shorts.
I took the a/b switcher apart and took some pics which I will attach. All the solder joints looked OK. I’m not sure if the wiring is correct or not. I’ll defer that to you. I did find one of the solder joints on the input jack (i’m not sure if it was the tip, ring, or sleeve ) had a loose strand of wire that could have been touching another wire and grounding, so I pushed it back so it wasn’t sticking out. I don’t know if that helped or not, but where is before only one light came on now both lights come on win a TRS cable is inserted into the input and either button is pushed. The lights go off when the button is pressed the second time. So I had Hope after this improvement.
However, when I plugged the baby switch back into the PBC 6x and pushed the AMB button, nothing happened on the PBC 6x. The blue and red lights on the ABC switcher turn on and off appropriately, but there is no effect from the button on the PBC6x.
Will try to send you my Editor file in another reply.
By the way, I wish you still sold your AB switcher. I would have bought it.
Thanks.