LG GT500 - Page 126

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Only for training and service purposes
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4. TROUBLE SHOOTING
Main Board (Bottom side) : Power for Radio ASIC
f
4.16.4 Checking VCC
AB3100
TP1
TP2
f
2.8V OK?
No
Yes
1.8V OK?
Yes
No
Check the AB31000
Check the AB31000
Check Point
VDIGRAD_1V8
(TP2)
Common Input Power is OK
See The Next Part
Check Point
VRADA_2V8
(TP1)
to RF3300 digital
to All I/O Supplies and Memory
to RF3300 Power Detector
to AB3100 CODECs/ADC/PLL
VDDA_2V8
VDDH_2V75 VDDF_2V5
0R303
R304 0
R305 0
2.2u
C303 C304
2.2u
VDDC_2V65
O
A_OUT
K13
O
D OUT
L12
G14
C12
E
XT_LDO
0R302
C302
2.2u
VDDK_2V75
VDDD_2V65 VBAT
VDDG_2V85
VDDE_1V8 VDIGRAD_1V8
VBAT
EXT_LDO
VDDD_2V65
VDDA_2V8
VDDE_1V8
VDIGRAD_1V8
TP1
TP2
AB3100