Checked Bias transistors both with heat gun and are reacting so seems closer to operating Id like to make it function before I tear it apart and do the WOPL upgrade just to have an understanding.
Like I said in a previses post,
Visual inspection and sometimes I use a Magnifying glass after cleaning w isopropyl alcohol w a tooth brush.
I would clean the board and look for bad solder joint but really look for crack and broken traces and wires. ever time you work on the phase linear and move something, it can cause a broken wire or they come loose and also check the wires to the little Bias transistor and they also tend to break off. And every time you unsolder something the solder pads can lift up, if you are not carefull. A visual inspection has to be done before turning power on every time you work on it.
Than I would check the bias transistor and the pot and than the traces from each leg of the pot and buzz it out to the next component leg. I put the meter lead on the pot leg and than to the component leg and any places that might look bad.
and in any area that might have a bad traces, your problem is in this area first. than you can compare it to the other Left channel
(and ohm the pot out to, I had all of these problems)
Good luck, your getting closer