coco wrote:
Disconnect all the wires from the circuit, then use a digital ohm meter to measure the following resistances.
OK, I assumed you meant disconnect the OT wires, which I did. I did not check the blue/white or brown/white wires because they are tied and heatshrink closed outside of the chassis. The other readings came out close to what you indicated:
Primary
Brown - Red: 271 ohms
Blue - Red: 326 ohms
Brown - Blue: 600 ohms
Brown/White - Blue/White: 326 ohms
Secondary
Black - Orange: 1.0 ohms
Black - Green: 0.8 ohms
Black - Yellow: 0.6 ohms
While the rotary switch was disconnected, I checked continuity on the switch terminals. I assume that the switch toggles connections between the different OT wires and the "hot" wire. The switch shows continuity between the 4 Ohm terminal and the hot wire when 4 Ohms is selected. There is no continuity at the 8 and 16 ohm terminals when those are selected. Doesn't that mean the switch is bad?
Should I run the amp with the 8 ohm wire directly connected to the "hot" wire? I imagine that if that works, we can assume that the OT is ok, and the switch is bad. But I'd like you to confirm that this is safe before I proceed. Thanks, CR