Any help in the manual about using front panel controls? My avrs (I don't have your model) generally have enough control on the front panel to do basic things like sound mode, but wouldn't surprise me if quite a few functions are restricted to the remote and a gui on a tv these days.
I'd try and get the original model of remote at least and probably the mic unless you have other setup tools (like an spl meter or measurement mic)....a modern avr isn't really complete without them.
You say you get sound out of all channels but don't have all channels hooked up to speakers? What is your speaker setup at this time?