LG U8110 Service Manual page 172

C. GSM RF Transceiver IN/OUT Signal Check
N1331
MODA
(R1213)
MODB
(R1212)
MODC
(R1211)
MODD
(R1210)
Check Mode(A/B/C/D)signal at
Check if there is any Major difference.
Refer to right side of
Check GSM RF Transceiver
Output power at
Check GSM/DCS Tx Balun
output power at
DCS Tx GSM T x
(R1341) (R1338)
N1330
Figure 4-43. GSM Tx MODE signal
.
Figure 4-43.
GSM/ DCS
.
GSM/DCS
.
See next page to check Tx path
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4. TROUBLE SHOOTING
GSM Tx
(L1330)
DCS Tx
(L1331)
No
Simiar?
Yes
No
>- 5dBm
Yes
No
>- 7dBm
Yes
MODA
MODB
Resoldering MODE block
(R1210,R1211,R1212,R1213)
Redownload SW
Resoldering Tx Balun
GSM : N1330
DCS : N1331