LG CG225 Service Manual page 88

4.17.5 Checking PAM Control Signal (Tx pass continued)
GSM_OUT
8
GND23
32
U501
GND22
31
GND21 RF3166
30
GND20
29
GND19
28
GND18 TX_ENABLE
27
GND17
26
BAND_SELECT
DCS_PCS_OUT DCS_PCS_IN
9
APC
Check AP C,
PA_ON, PA_BAND
Norm al?
Yes
Cont rol signal is OK . See next page t o
Check FE M & Mobi le SW
VBAT
C504 C501 C502
33u 0.1u 47p
GSM_IN
7
R517
VRAMP
6
C539 0
GND 27p
5
VBATT
4
3
2
1
4. TROUBLE SHOOTING
No
Downl oad the S W
C503
10p
- 87 -
R501 24
R503 R502
C505
220 220 0.1u
R504 20
R505 C513
R506
100p
10K
300
APC
PA_ON
RFOL
APC
PA_ON
PA_BAND
RFOH