I came across an old Onkyo TX-SR600 receiver and I'm having trouble with my surround left/right not playing anything at low and mid volumes. I have a 5.1 setup, and there is no sound out of them at all until I crank the volume up, at which point they seem to work fine (but it is too loud for everyday listening levels). I've gone into the individual speaker setup to balance levels, and there is no white noise (which the system plays for the user to balance) from the surrounds until I turn them up to something like +10dB, at which point they turn on and loudly play the white noise. Once they have "kicked in", I can turn the dB level back down to 0 and they work... for a little while. Usually after a minute or two, they stop playing sound again.
I can repeat the above procedure every time, so it seems the surround aren't "kicking in" until I turn the volume way up and/or individually adjust the level up for them.
I know the speakers and wires are fine, as I just moved them from another Onkyo receiver, the similar SR-500.
Does anyone have any clues as to why this might be happening?