LG KG290 - Page 66

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4. TROUBLE SHOOTING
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(4) Checking TX I/Q
U501
C541
C514
0.1u
C519
VCC_REF
12
VCC_TXVCO
VDD
13
VLDO1
15
16
VLDO2
VLDO3
9
RX1900
RX1900B
25
32
RX850
RX850B
31
30
RX900
RX900B
29
6
SCLK SDATA
5
SEN
7
TXOP_HI
11
10
TXOP_LO
VAFC_NC
18
14
VBAT
4
VCC_BBI
VCC_BBQ
24
VCC_FE
1
17
33
GND
2
I IB
3 8
NC
23
Q
QB
22
REFIN
20 19
REFINB
21
REF_OP
28
RX1800
RX1800B
27
26
U501
AD6548
39p
C541
39p
C514
0.15MM
IN
QN
QP
IP
Re-download the Software
And calibrate
Check if there is
Any
Major Difference
Refer to Graph4.3.4
Similar?
Yes
No
Replace U501
TEST POINT
CIRCUIT
Checking Flow
Waveform
Graph 4.3.4
Figure 4.3.4