Usb Trouble - LG GD910 Service Manual

5. Trouble shooting

5.4 USB Trouble

Checking Flow Checking Flow Checking Flow Checking Checking Checking Flow
Checking Flow
Start Start Start Start
Is Cable inserted?
Cable is insert? Cable is insert? Cable is insert?
Is USB_VBUS(C304)
Is USB_VBUS(C447)
USB_VCHG(C242) is USB_VCHG(C242) is
about 5V?
about 5V?
about to 5V? about to 5V?
Check TP1
Check TP1
Is OVP_VUSB(C303)
OVP_VUSB(C245) is OVP_VUSB(C245) is
Is OVP_VUSB(C446)
about 5V?
about to 5V? about to 5V?
about 5V?
Check TP2
Check TP2
Is VDD_CHARGE Is VDD_CHARGE
VDD_CHARGE(C202) is VDD_CHARGE(C202) is
about to 4.8V? about to 4.8V?
about to 4.8V? about to 4.8V?
Check TP3
Check TP3
Is USB function ok? Is USB function ok?
USB function is ok? USB function is ok?
END END END END
LGE Internal Use Only
NO
YES YES YES YES
NO NO NO NO
YES YES YES YES
NO NO NO NO
YES YES YES YES
NO NO NO NO
YES YES YES YES
NO NO NO NO
GD910 service manual
Cable insert Cable insert Cable insert Insert Cable
Change cable Change cable Change cable Change cable
Check soldering or Check soldering or Check soldering or Check soldering or
change U203 change U203 change U300 change U407
Check soldering or Check soldering or Check soldering or Check soldering or
change D202 change D201 change D202 change D300
Change U202 or Change U202 or Change U201 or Change U200 or
main board main board main board main board
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