![background image](http://html.mh-extra.com/html/samsung/sgh-t400/sgh-t400_service-manual_1191122031.webp)
Flow Chart of Troubleshooting and Circuit Diagrams
5-7
5-4 Sim Part
Q304 pin 5 = "H" ?
Replace Q304 or
Replace PBA
END
Yes
No
Check the circuit around U408
(Serial EEPROM) and data stored in it
Yes
Phone can't access SIM card
Yes
Q304 pin 2, 3 = 3.0 V ?
Replace Q304
Yes
No
After Power ON,
Check SIMCLK Signal on CN302 pin 3
in a few second
After SIM card insert,
CN302 pin 2 = "H"(SIMRST) ?
Replace PBA
Replace PBA
Yes
No
No
Q304 pin 4 = 3.0 V ?
Yes
No
Resolder R338
Summary of Contents for SGH-T400
Page 2: ...Samsung Electronics Co Ltd Printed in Korea 12 2002 Rev 1 0 GH68 03158A ELECTRONICS ...
Page 11: ...2 1 PCB Diagrams 2 PCB Diagrams 2 1 Main Top ...
Page 12: ...2 2 PCB Diagrams 2 2 Main Bottom ...
Page 26: ...Flow Chart of Troubleshooting and Circuit Diagrams 5 2 ...
Page 30: ...5 6 Flow Chart of Troubleshooting and Circuit Diagrams ...
Page 38: ...5 14 5 8 Receiver Part Flow Chart of Troubleshooting and Circuit Diagrams ...
Page 39: ...5 15 Flow Chart of Troubleshooting and Circuit Diagrams ...
Page 40: ...5 16 Flow Chart of Troubleshooting and Circuit Diagrams 5 9 Ring Indicator ...
Page 43: ...5 19 Flow Chart of Troubleshooting and Circuit Diagrams 5 12 GSM Receiver ...
Page 44: ...Flow Chart of Troubleshooting and Circuit Diagrams 5 20 5 13 GSM Transmitter ...
Page 45: ...5 21 Flow Chart of Troubleshooting and Circuit Diagrams 5 14 DCS Receiver ...
Page 46: ...Flow Chart of Troubleshooting and Circuit Diagrams 5 22 5 15 DCS Transmitter ...