LG -H845 Service Manual page 28

Checking DRX RF signal path (LTE1/2/3/4/5/7/8/12/17/20/28A/28B/38/40 MIMO)
Checking Flow
START
Check TP1/2/3/4,
High Level?
(2.5V≤TP1 ≤3.1V)
(1.7V≤TP2 ≤1.9V)
YES
Check TP5/6/7
Signal exist?
YES
Check TP8
Signal exist?
YES
Check TP9/10
Signal exist?
YES
Check TP11/12
Signal exist?
YES
Check TP13/14
Signal exist?
YES
Check Transceiver
physical damage
or soldering condition
OK?
Check next step
LGE Internal Use Only LGE Internal Use Only
The Problem may be Logic part
Refer to Logic trouble shoot
NO
Check B1/B4, B2/B3,
B5/B8 and U1100
NO
Soldering
Check B12/17/20/28 and
U1102 Soldering
NO
Check B39/B40 and
U1100 Soldering
NO
Check B7 and B38
Soldering
NO
Check B2/3/39 , B7/B38 and
U1103, FL1013 Soldering
NO
Replace U1500/U1501
NOT GOOD
TOP
TP4(1.8V)
TP12(LTE B38/41)
FL1013
TP11(LTE B7)
TP3(2.7V)
TP7(LTE B5/8)
TP8
(LTE B12/17/20/28)
BOTTOM
27
3. TROUBLE SHOOTING
Image
TP2(1.8V)
TP1(2.7V)
U1100
TP6(LTE B2/3)
U1102
TP5(LTE B1/4)
U1103
TP14(LTE B7/38/41)
U1500
U1501
TP9(LTE B39)
TP13(LTE B2/3/39)
Copyright ⓒ 2016 LG Electronics. Inc. All right Copyright ⓒ 2016 LG Electronics. Inc. All right
reserved. Only training and service purposes reserved. Only training and service purposes
BOTTOM
TP10(LTE B40)