5-7
Flow chart of trouble shooting
5-4 Sim Part
U300 pin4,6 = 3V ?
U300 pin5 = "H" ?
Check the circuit related to U102
END
Replace the PBA
Yes
No
No
U300 pin2,3 = 3V ?
CN301 pin3,7 = 3V ?
Replace U300
Resoldering CN301 and check open
connection from U300 to CN301
Yes
Yes
No
No
After Power ON,
Check SIMCLK Signal on CN301 pin 1
in a few second
After SIM card insert,
CN301 pin 2 = "H"(SIMRST) ?
Replace the PBA
Replace the PBA
Yes
Yes
No
No
Check the circuit around U504
(Serial EEPROM) and data stored in it
Yes
Phone can't access SIM card
Yes