Panasonic TC-P50S1 User Manual

Slide #39

System MPU SOS Detect

IC5401 generates the SUB9V, IC5607 generates the SUB5V, and IC5480 

generates the BT30V. The SUB9V, BT30V, and SUB5V from these ICs are monitored by IC1100. 
Any abnormality on these voltages (Including the F_STB15V), triggers the shutdown circuit and the 
MPU shuts down the unit. The power LED blinks 10 times.

The ventilation fans are monitored for proper operation. If one of the fans opens or 

increases resistance, the resulting current change is applied to pin 36 of the main CPU (IC1100). 
This triggers the Fan SOS and the TV shuts down. The power LED blinks 11 times.

The operation of the audio power amplifier IC2109 is monitored. If the audio output 

circuit develops a short to ground, a high is output to pin 37 of the MPU (IC1100), triggering a SOS 
condition. The power LED blinks 12 times.

:  When the TV is turned on, a system check is performed through the IIC0 bus line. 

The system MPU and IC8001 (Seine 3LV) communicates and if an abnormality is detected, the TV 
shuts down and the power LED blinks 13 times.