LG GB220 - Page 66

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
(1) Checking Crystal Circuit
TEST POINT
CIRCUIT
WAVEFORM
CHECKING FLOW
Figure 4.2.1
X100
1 pin : 26MHz
26 MHzO.K?
No
Crystal is OK. See next page to
check PLL Circuit
Yes
Replace X100
Figure 4.2.2 Figure 4.2.3
2V85_VSIM
GND
4
1
TER1
2
TER2
XTAL
3
EXXY0026401
FA-20H
X100
26MHz
C125 0.1u
EOC
nLCD_RESET
UART_TX
UART_RX
USB_P
SIM_RST
SIM_CLK
SIM_DATA
USB_N
1 pin