LG -H845 Service Manual page 31

LTE1/2/3/4/5/7/8/12/17/20/28A/28B/38/40 Tx
Checking Flow
START
Check TP1
+VPWR OK?
NO
Check TP2/20
3.2V≤TP2≤4.2V?
NO
Check TP3/4/5/6/7/8
/9/10/11/12/13/14/15
If LTE B1/2/3/4 Over 22.5dBm?
LTE B7 Over 22.2dBm?
LTE B5/8 Over 23dBm?
NO YES
LTE B38 Over 23.5dBm?
LTE B12/17/20/40 Over 24dBm?
LTE B28 Over 24.3dBm?
Check TP16/17/18/19/20
If LTE B1/2/3/4/5/7/8/12/
17/20/28/38/40
YES
Over 3dBm?
NO
NOT GOOD
Check Transceiver
physical damage
or soldering condition
OK?
Check next step
LGE Internal Use Only LGE Internal Use Only
The Problem may be Other part
Check Logic part
Check DC-DC Power Block
Check component
above RF signal path
TP2(+VP0)
Check U1300 soldering
TP1(+VBAT)
Replace U1500/U1501
Image
BOTTOM
TP18(LTE B12/17)
U1300
TP7 (LTE B8 Tx)
TP8(LTE B12/B17 Tx)
TP10(LTE B28A Tx)
TP11(LTE B28B Tx)
30
3. TROUBLE SHOOTING
TP17(LTE B5/B8/20/28)
TP16(LTE B1/B2/B3/B4/39)
TP19(LTE B7/B38/B40/B41)
TP15 (LTE B38/41 Tx)
TP14 (LTE B40 Tx)
TP4 (LTE B3/4 Tx)
TP3 (LTE B1 Tx)
TP12 (LTE B39 Tx)
TP5 (LTE B2 Tx)
TP6 (LTE B5 Tx)
TP9 (LTE B20 Tx)
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
TP20
TP13 (LTE B7 Tx)