Gsm Transmitter - Samsung SGH SGH-D500 Service Manual

Flow Chart of Troubleshooting

13. GSM Transmitter

TX ON (5Level)
Yes
U100 Pin7
>= 20dBm
Yes
U100 pin10
>= 18dBm
Yes
PAM100 pin16
>= 18dBm
Yes
PAM100 pin5
>= -11dBm
Yes
OSC100 pin1
>= -15dBm
Yes
U102 pin6, 7, 8, 9
>= 1V
Yes
Check U205
END
No
Resolder RFS100, C102, L106
No
No
Resolder C134, L108, C149
No
No
Resolder R114, R116, R117
No
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Check U100
pin4 = H (2.68V),
pin2,8 = L
Yes
No
Check PAM100
+VBAT,
pin2,3,13,14 OK?
Yes
Check U102
No
pin23, 26, 31
>=2.7V
Yes
7-24
No
Check ANT Switch
control circuit
Change or Resolder U100
Resolder or Change PAM100
Check +VBAT or PAM
control signal
Check & Resolder RFLO
signal, RF13MHz,
RF PSU Part
Resolder U102