LG -T300 Service Manual page 68

(1) Checking Crystal Circuit
TEST POINT
Figure 4.3.1
CIRCUIT
LCD_BL_CTRL
Connect GND plane directly
Close to the 26MHz XTAL
X101 DSX321G-26M
4 3
1 2
26MHz
TP1
TP1
Figure 4.3.2
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Only for training and service purposes
X101
TP1_1 pin : 26MHz
H8
BT_RESET
USIF2_TXD_MTSR
J7
USIF2_RXD_MRST
H7
nLB
USIF2_RTS_N
J8
nUB
USIF2_CTS_N
A2
UART_TX
USIF1_TXD_MTSR
B3
UART_RX
USIF1_RXD_MRST
A3
BT_RXD
USIF1_RTS_N
B2
BT_TXD
USIF1_CTS_N
K11
USB_DP
DPLUS
K12
USB_DM
DMINUS
B11
XOX
A11
XO
4. TROUBLE SHOOTING
CHECKING FLOW
26 MHz O.K?
Yes
Crystal is OK.
See next page to check PLL Circuit
WAVEFORM
Figure 4.3.3
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4. TROUBLE SHOOTING
No
Replace X101
TP1
LGE Internal Use Only