One thing you might want to be very careful about is that the speaker wires at the left speaker end are not touching or any other condition that might be causing a short downstream of the amp on the left side. A long shot but if they amps were swapped in sequentially with that condition staying the same, it could cause the left channel in all three amps to go out.
All my amps have left speaker out??
I have 3 amps and 2 preamps. All amps have a Left speaker out. Is it possible for a preamp or component to blow out left speaker channels when it gets hooked up to any amps?
2 parasound amps
2 parasound preamps
Audiophile amp
Parasound cd
Arcam cd
Parasound tuner
Parasound video controller
Harmon kardon tape player
Audio technica turntable
NHT speakers