5-16
SGH-N500 Flow Chart of Troubleshooting and Circuit Diagrams
5-9 Ring Indicator
Ring Indicator LED does not
work
Check the circuit related to U621
U621 pin 3 3.0V?
Is Green color of
3 LEDs correctly work?
Is Red color LED of
3 LEDs correctly work?
Check Q408,R727,LED1
END
Check Q407,R726,LED1
Yes
No
Yes
Yes
No
No
Is Blue color LED of
3 LEDs correctly work?
No
Check Q406,R728,LED2
Yes