Steelman
Super Member
Just to be clear, its the left channel that is not putting out any sound and your measurements are
Left: 00.7 millivolts
Right: .27 millivolts
or did you mean
Left: 00.7 volts (ie 700 millivolts)
Right: .27 volts (ie 270 millivolts)
iirc your Fluke meter will autorange on voltage unless you have it set to the 300mv range.
The bias pots are the blue and brown devices next to the large square heatsinks with the circular metal transistors. I wouldn't mess with them except to clean or replace.
I'd check for bad solder joints around the aforementioned transistors, by the large rectangular white resistors on the left of the board and the 2 large brown resistors on the circuit board. The transistor sockets on the right should be checked as should their associated resistors. Large carbon comp resistors often go off-tolerance or physically crack.
Okay...
I finally had a chance to check. All the solder joints look good. I checked for ringlets, scorching and any chacks with a illuminated magnifier...no physical cracks on the large carbon comp resistors...