LG LG-H815 - LTE1;2;3;4;5;7;8;17;20;28 A;28 B Tx

Copyright ⓒ 2015 LG Electronics. Inc. All right
reserved. Only training and service purposes
LGE Internal Use Only
3. TROUBLE SHOOTING
3.7.2 LTE PART
Checking Flow Image
Check TP1 /TP3/TP4
+VPA0 OK?
START
The Problem may be Other part
Check QFE2101 Logic part
NO
The Problem may be Other part
Check QFE2101 Logic part
Check TP2/TP16
3.2V≤TP2≤4.2V?
Check TP5/6/7/8/9/10/11/12/13/14/15/16/
If LTE of All band Over 22dBm?
NO
Check next step
Check component
above RF signal path
YES
YES
Replace U1300
NO
Check Transceiver
physical damage
or soldering condition
OK?
NOT GOOD
Replace U1500
U1300
TP4
BOTTOM
TP1(+VPA0)
U1400
TP2(+VPWR_BOOST_BYPASS_RF)
TOP
LTE1/2/3/4/5/7/8/17/20/28A/28B Tx
YES
TP7(Band3 Tx)
TP5(Band1 Tx)
TP8(Band4 Tx)
TP6(Band2 Tx)
TP9(Band5 Tx)
TP10(Band8 Tx)
TP3((+VPA0)
NO
YES
Check TP5/6/7/8/9/10/11/12/13/14/15/16/
If LTE of All band Over 10dBm?
28