LG GU280 Service Manual page 45

4. TROUBLE SHOOTING
4.3.4 Checking GSM Tx part
Checking Flow
Setup Test Equipment
Cell Power = -60dBm
Tx Power Level Set
(GSM=5, DCS=0, PCS=0)
Is the level of
TP4, TP5 same
to Table.1?
TP2, 30dBm over?
TP3, 33dBm over?
Check TP1
GSM850, EGSM 32dBm
DCS, PCS 29dBm
over?
Re-download & Calibration
Checking Points
LGE Internal Use Only
No
Yes
No
Yes
No
Yes
TP3
TP1
TP4 : Check U201
TP5 : Check VBAT Line
Remove U101 and check
the power of pin1, pin8.
(on board)
Yes
The power of pin1, pin8
Is over 0dBm?
Yes
Replace U101
TP4
TP5
TP2
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No
Check U201
Only for training and service purposes