SAMSUNG Proprietary-Contents may change without notice
5-17
SGH-A400 Flow Chart of Troubleshooting and Circuit Diagram
5-12 SGH-A400 GSM Transmit
Tx On (level : 5)
Battery voltage : 3.8 V
Using 20 dB Attenuator
N
Y
Y
U505
Pin 9
≥
30 dBm
Resolder
CN500
LAM1
Pin 3
≥
30 dBm
Resolder or Change
LAM1
Y
Y
Y
Change
U510
END
Y
N
Y
Change OSC300
N
N
N
U510
pin 4
≥
0 dBm
Y
Resolder or Change
U505
Y
N
U505
Pin 1
≥
30 dBm
N
N
Resolder or Change
U503, Q501
Y
Resolder or Change
U512
Y
Change U300
N
Change
U508
Check voltage
Pin 2 : H
Pin 4 : L
Pin 8 : H
Pin 10 : L
U513
Pin 9 : H
Pin 7 : L
U513 pin 3
1~2.3V ?
Check
OSC300 pin1
≥
-10 dBm
Check
U510 pin14
1V ~ 2V ?
Change U513
1
2
3
4