Only For Training And Service Purposes - LG KP175 Service Manual

(4) Checking TX I/Q
TEST POINT
U502
C507
Figure 4.3.4
CIRCUIT
CHECKING FLOW
Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes

C530
C514
0.1u
RX1900B
25
RX1900
26
RX1800B
U502
27
RX1800
28
RX900B AD6548
29
RX900
30
RX850B EUSY0280101
31
RX850
32
GND
33
C525 C526
27p 39p
Check if there is
Any Major Difference
Refer to Graph4.3.4
Re-download the Software
And calibrate
4. TROUBLE SHOOTING
WAVEFORM
Graph 4.3.4
QP
C507
DNI
QN
2V75_VVCXO
C513
0.1u
VLDO2
16
VLDO1
15
VBAT
14
VDD
13
VCC_TXVCO
12
TXOP_HI
11
TXOP_LO
10
VLDO3
9
IP
C530
DNI
IN
No
Replace U502
Similar?
Yes
- 51 -
LGE Internal Use Only