Aiwa HV-FX7800 Service Manual page 46

ELECTRICAL TROUBLESHOOTING -6/17
B.
Drum Motor stopped.
Does 12V appear at PMD01 Pin 4?
Does 2.8V appear at PMD01 Pin 1?
Check Connector and Drum Motor Ass'y.
Check the Components and foil Pattern
between IC501 Pin 107 and PMD01
Pin 1 for shorts.
Do DFG Pulses appear at IC501 Pin 104?
Does the Drum PWM waveform
appear at IC501 Pin 107?
Check the Components and foil Pattern
Connected to IC501 Pin 107 PMD01
Pin 1 for shorts.
YES
YES
YES
YES
YES
NO
NO
NO
NO
-46-
Check Power.
Does Drum PWM appear at IC501 Pin
107?
NO
Do DFG Pulses appear at PMD01 Pin 3?
NO
Check Drum Monitor Ass'y.
Check the Components and foil pattern
between PMD01 Pin 3 and IC501
Pin 104 for shorts.
Replace IC501.