LG GT500 - 4 Trouble Shooting; Power on Trouble

- 73 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
4. TROUBLE SHOOTING
4.1 Power ON Trouble
START
No
Change main board
change
main battery
Yes
Yes
No
No
The voltage of main battery
is higher than 3.3V ?
END key operates well?
UART_TX(TP1) level is 1.8V
when END key pressed.
Follow the
keypad Trouble
shooting guide
Check the voltage.
VDDA_2V8 (TP2) 2.8V
VDDD_2V65 (TP3) 1.5V
VDDE_1V8 (TP4) 1.8V
VDDC_2V65(TP5) 2.65V
VDDH_2V75(TP6) 2.75V
VDDF_2V5 (TP7) 2.5V
VDDG_2V85 (TP8) 2.75V
VDDK_2V75(TP9) 2.75V
VCORE(TP10) 1.2V
TP2
TP3
TP4
TP5
TP6
TP7
TP8
TP9
TP10
< Main Board – Bottom side >
4.1 Power ON Trouble
4.1 Power ON Trouble
TP802
TP800
TP804
TP801
TP803
OTP_SUB
APP_ACC_UART_TX
CTS_ON
VPPFLASH_E
APP_ACC_UART_RX
BLM18PG121SN1J
to RF3300 digital
120ohm 1608 2A 50mohm Bead
to Hall Switch and AB3100 BEAR
to All I/O Supplies and Memory
to RF3300 Power Detector
to SD Card and LCD
to Bluetooth
to AB3100 CODECs/ADC/PLL
2.8*2.6*1.0 0.7A 240mohm 20%
to DB3210 CORE
Parallel with VCORE
1608
to DB3100 analog
to 3xis
Local ground plane
VDDA_2V8
4.7uH
L300
C309
VDDH_2V75 VDDF_2V5
1u
0R303
R304 0
R305 0
0R310
VCORE
VBAT_C
R307 0
VBAT
2.2u
C303
C310
4.7u
C304
2.2u
RB521S-30
VDDC_2V65
D300
C311
1u
R312 0
10u
C315
2.2u
C307
0R302
R309 0
1u
C312
C302
2.2u
C319
0.1u10u
C317C314
0.1u
0R306
10u
VDDK_2V75
C318
4.7K
R311
VDDD_2V65 VBAT
VDDG_2V85
1u
FB300
C308
VDDE_1V8 VDIGRAD_1V8
0R308
VDDC_2V65
VDDH_2V75
VDDG_2V85
VDDF_2V5
VBAT
EXT_LDO
VDDD_2V65
VDDA_2V8
VCORE
VDDK_2V75
VDDE_1V8
VDIGRAD_1V8
VBACKUP
TP1
TP2
TP3
TP4
TP5
TP6
TP7
TP8
TP9
TP10