With the indulgence of the others...
If I understand your problem right:
1. CD works only in Speaker A (but not in Speaker B);
2. DVD works on either or both A/B;
3. CD will work if plug into to VCR input but selector must be of another source (not VCR).
A couple of suggestions:
a. pls try doing again the reset as ginko
has suggested but make it a bit longer, i.e. unplug it from the mains for a couple of hours;
b. since you have remove most of the wiring, why dont you try switch A & B. make the family room speakers the B while the speaker selector the A;
c. hook the CD (only) using the RCA cables (red/white) nothing else;
d. play any CD music and go through the paces of selecting source, speakers, surround/hall/theater/etc as troylove11
This would be now a simple setup, 1 source (CD) to 1 output/speaker (the family room) via the Denon. Try different settings. If the CD plays normally then, without changing any setting nor powering it off (but with volume level all the way down), remove the family room speaker wiring and replace it with the wires to/from the speaker selector.
the idea is to determine which is the real issue, the Sony, the Denon settings/hardware or the speaker selector.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
Good luck and kind regards.
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