5-7 Key Data Input
Check Initial operation
the pin 19,20,21,22 and 23
one of the keys is pushed,
one of pin 19,20,21,22 and 23 of
5-12
Yes
Are
of CN503 low?
Yes
When
CN503 is high ?
Yes
Key PCB is OK ?
Yes
END
No
Replace the PBA
No
Resolder pin 19,20,21,22 and 23
of CN503
No
Replace the Key PCB
Flow chart of Troubleshooting and Circuit Diagram