LG KF510C Service Manual page 107

5. Trouble shooting
5.13.3 Checking TX I/Q Signals
FE2
33
VBIAS
34
VDDTX1V5 VDDRX2V8
35
TX1 VDDRX1V5
U402
36
TX2 VCO_RC
PMB6272
37
VDDTX2V8 VDDVCO2V8
38
VDDMIX2V8
39
GND3 VDDXO2V8
40
GND4
41
TP4(QX)
TP1(I) TP1(I)
TP3(Q)
TP2(IX)
U402
TP1(I) TP4(QX)
TP2(IX)
TP3(Q)
LGE Internal Use Only
0.1u 0.1u
20 C434
19 R406 47n
18 820
17
EN
16
15
FSYS1
14
GND1
13
C441
1000p
BT_CLK
RF_CLK
RF_DA
QX
Q
IX
I
Chec k TX I/Q Sig nals (TP1~TP4)
Sign als are
Normal ?
Yes
TX Part is O K.
Check B ase B and Circuit
or
Re-Download S/W and Cal
I
Q
I
Q
Copyright © 2008 LG Electronics. Inc. All right reserved.
- 108 -
No
Replace
Transc eiver
PMB6272(U402)
TX
Only for training and service purposes