01-08-2015, 10:59 PM
1. Oh....how about powering main amps without speakers!
2. See if C15 - C18 are not shorted.
3. Put VR3 and 4 to the shorted (minimum resistance) psoition.
4. Measure +B voltage and at the same time the voltages at C13 and C14 Positive. Those should be about half of B voltage.
5. Measure voltage between the Bases of Q5 and Q7, and same air in the other amp (cannot make the ref designators).
2. See if C15 - C18 are not shorted.
3. Put VR3 and 4 to the shorted (minimum resistance) psoition.
4. Measure +B voltage and at the same time the voltages at C13 and C14 Positive. Those should be about half of B voltage.
5. Measure voltage between the Bases of Q5 and Q7, and same air in the other amp (cannot make the ref designators).