Must be an old BOSS.
There is a small terminal strip to the right of the logic boards. I remember that there were wires 76 there. Three blue wires and three lavender wires. Very thin. These wires are what I use to measure the logic voltages at the boards. The blue and lavender wires next to each other are the 5 VDC and adjust the trim pot for 5VDC. go out one wire in each direction, and I believe this is the 12VDC. The two outside wires are the -12VDC. The regulating board is silk screened with what each multi turn pot adjusts. If I remember correctly the 5 VDC pot is on the bottom. That is the most critical. You will find about a .1 to a .2 VDC difference between the test points and these wires. The wires are a more accurate way of setting these voltages.
George
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