My sx601 zone two speakers(two pair on a switch)stopped working along with with subwoofer after I had to after unit would not power up and I unplugged to reset. Unit has been to repair shop and no problem found. All spkrs work including zone two pair. I placed a 2 channel stero on the switch and both pair play. Onkyo support had me move some spkr wires around, and the zone two's played. When I put it all back, they no longer. Onkyo said that proved I had a bad spkr somewhere. How can that be if all spkrs play? Anyone know how to fix this..

Well, it's probably that "two pair on a switch" thing. If you're trying to play them simultaneously, the impedance probably drops much too low for the zone 2 amp to push. If you're only playing them one pair at a time, perhaps it is the switch.

I have tried just one pair at a time on the switch and it still will not work. It has worked for 5 years up until I had to unplug the unit to reset it....

Have you tried just one pair directly to the amp and NOT through the switch?

yep sure have. I even disconnected the spkrs from the patio, both pair, connected them directly to zone two and they played. Also, I bypassed the switch by taking the skpr wire that inputs to the switch and twisted the wire onto one pair, and they would not play. Now if I hook up my old 2 channel to the switch, both pair will play. go figure. makes no sense to me whatsoever. Sure sounds like something wrong with the unit, but the repair said everything works...

From the sound of it, the Onkyo isn't handling the lower impedance of the two zone two pairs. What's odd is that you said that it used to. That's not something that should change!