Wireless speaker schematic?

I am a "newbie" at electronics and electronics troubleshooting. My first project, hopefully, is to find out why only one speaker of a pair of wireless speakers works. I've so far read 11 books on electronics and troubleshooting so I am getting more familiar with vocabulary and identifying parts. I don't yet recognize the simpler circuits embedded in a more complex design (complex to me anyway). I have a DC power supply, both a DMM and analog multi-meter, and ESR meter, and an older dual channel oscilloscope. Along with a bunch of hand tools and desire, that's about it. I've tried to find a schematic for these speakers but haven't been able to find one. They are AR-871's made by Acoustics Research. Any help locating the schematic, any hints on working through this problem, any and all assistance greatly appreciated as I embark on what I hope will be a fun-filled hobby for my retirement years. Thanks to all who've taken the time to read my post!! Kevin :-)