LG LG-H815 - Page 31

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3. TROUBLE SHOOTING
3.7.3 LTE PART
Checking Flow Image
TOP
TP13(Band20 Tx)
TP12(Band17 Tx)
TP14(Band28A Tx)
TP15(Band28B Tx)
TP11(Band7 Tx)
TP4(+VPA0)
U1300
U1750
TP16(+VPWR_BOOST_BYPASS_RF)
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
YES
NO
YES
Check TP5/6/7/8/9/10/11/12/13/14/15/16/
If LTE of All band Over 10dBm?
LTE1/2/3/4/5/7/8/17/20/28A/28B Tx
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