Panasonic TH-65PX600U Service Manual page 46

D Board SOS Detect
Power supply abnormalities detected on the P board are reported to IC9003 via the SOS4
input. SOS2_15V, SOS3_3V and SOS5_5V of IC9003 monitor for a short circuit of the
15V, 3.3V and 5V inputs to the D board. The DRV RST input monitors for the presence of
5V on the C boards. The remaining SOS inputs monitor for abnormal operation of the SC
and SS boards.
Since the D board does not control the blinking pattern of the power LED, any detected
SOS condition must be reported to the DG board MPU (IC1103). The alarm pin of IC9003
reports all SOS detections to the DG board MPU.. The "ready" pin of IC9003 is an
acknowledgement line that reports to the DG board MPU, the operational status of the D
board.
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