Sony str-dg510 receiver speaker a/b mode not working correctly
My problem is: The receiver does not turn off the section A front speakers when Speaker B mode is selected.
This is a big problem because in order to hear the speakers from my porch in the backyard I have to turn the volume up very loud and since the front A speaker set stays on it's deafening inside the house. I have determined this happens regardless of the device plugged in and the type of cabling. I have tried an HDMI playstation, component xbox, using only composite cables on the cd player and the receiver still does not turn off the Front A speakers when B mode is selected. I have also tried every slot on the back of the receiver (cd, sat, tv, dvd) and the same problem occurs.
Why is the receiver not switching modes correctly? It is not turning off the front A speakers when Speaker B mode is selected. (It is however turning off the B speakers when A is selected).
I've included a diagram of how the system is currently wired: