I swapped the faders for channels 1 and 2 and here's what happened
I plugged a mic into channel 1, set everything to unity gain, assigned it to buss 1/track 1 and got signal. So the fader isn't the problem/
Then I plugged it into channel 2, assigned channel 2 to buss 2/track 2 and got, apparently, nada. I tried assigning channel 2 to buss 1/track 1 and got the same result as when it was plugged into channel 1 (so, a clear strong signal). I repeated this with both channels for the remaining six pgm busses/tracks, plus the stereo buss, and got the same result as I did for buss 1/track 1.
Just for the hell of it I decided to see what would happen if I tried monitoring buss 2 with the channel fader all the way up. I could hear something, so I pushed the buss B and stereo master fader to the top as well and recorded a short count to 12 to track 2. Playback through the monitor buss was lower in volume and somewhat distorted. Playback through the stereo buss on remix mode was fine. Even with the channel, Buss B and stereo master faders all at unity when recording.
I hope that made sense.