LG -H845 Service Manual page 19

GSM850/900/1800/1900 Tx
Checking Flow
START
Check TP1
+VPWR OK?
YES
Check TP2
3.2V≤TP2≤4.2V?
YES
Check TP3/4
If GSM850/900 Over 31dBm?
If DCS/PCS Over 29dBm?
NO
Check TP5/6
If GSM850/900 Over 9dBm?
If DCS/PCS Over 7dBm?
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
NO
Check DC-DC Power Block
NO Refer to 3.3
Check component
YES above RF signal path
Check U1300 soldering
YES
Replace U1501
U1300
TP1(+VBAT)
TP2(+VPA0)
TP3 (GSM HB Tx)
TP4 (GSM LB Tx)
18
3. TROUBLE SHOOTING
Image
BOTTOM
TP5(G900/G850)
TP6(DCS/PCS)
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reserved. Only training and service purposes reserved. Only training and service purposes