5-16
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 5 3.3V?
Is Green color of
3 LEDs correctly work?
Is Red color LED of
3 LEDs correctly work?
Check U651,R644,LED1
END
Check U651,R642,LED1
Yes
No
Yes
Yes
No
No
Is Blue color LED of
3 LEDs correctly work?
No
Check Q411,R728,LED2
Yes