Flow Chart of Troubleshooting and Circuit Diagrams
5-7
5-4 Sim Part
U101 pin5 = "H" ?
Replace U101 or
Replace PBA
END
Yes
No
Check the circuit around U402
(Serial EEPROM) and data stored in it
Yes
Phone can’t access SIM card
Yes
U101 pin 2, 3 = 3.0 V ?
Replace U101
Yes
No
After Power ON,
Check SIMCLK Signal on CN100 pin 3
in a few second
After SIM card insert,
CN100 pin 2 = "H(SIMRST) ?
Resoldering C109 or
Replace PBA
Replace PBA
Yes
No
No
U101 pin4 = 3.0 V ?
Yes
No
Check the circuit around U104