b. Return power circuit. The return power circuit provides operating
voltage to the AM-1780, KY-57 and R-442.
(1) The return power circuit at the MT-1029 J24 pin C applies voltage
through the MT-1029, J-3513, CX-4723 to the AM-1780 J501 pin C (Figure 42).
In the AM-1780, voltage is applied through the upper segment of switch S504
to CB501. From CB501 the voltage is applied through the AM-1780, CX-4723,
and the C-2298, as discussed earlier. (Trace these circuits on your system
Return power circuit.