Ok, so I had some time today to tinker and here's what I found, (in no particular order): Left channel is distorted, right may be very slightly. Touching the top of a cap on right channel makes a loud buzz (none others do). I found a coupling cap on left channel with 78 ohms ESR in preamp section. It has four "modes", Dolby pro logic, 3CH logic, Theater, and Stadium. both Dolby and 3CH logic are distorted while theater and stadium are not. The DC offset issue on the speakers is still there, but only when I switch it to Dolby and 3CH logic settings. so far where I think I'll start is with the preamp section, which is a patch of about 25 transistors and a dozen or so caps. The board is discolored from heat and I can see it with my thermal camera getting to almost 80c is some spots, that is near the temp rating of the caps. I would not be surprised if they are dried out after 25 years of that, this is where I found the coupling cap with high ESR (red top), and the one that doesn't like being touched (gold mark), in the picture attached below. Perhaps replacing the several small caps in that area will help a few of these issues. Also, I can't really find many coupling caps, is there an area I should look other than the beginning of the preamp circuit?