Usb Trouble - LG GW520 Service Manual

5.4 USB Trouble

Checking Flow Checking Flow
Start Start
Cable is inserted? Cable is inserted?
Is VBUS_USB (C306) Is VBUS_USB (C306)
about 5.1V? about 5.1V?
Check TP1 Check TP1
Does VMUIC_DM Does VMUIC_DM
connect USB_DM? connect USB_DM?
And does VMUIC_DP And does VMUIC_DP
connect USB_DP? connect USB_DP?
Check TP2 Check TP2
Is USB function ok? Is USB function ok?
END END
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Only for training and service purposes
NO NO
NO NO
YES YES
NO NO
YES YES
NO NO
YES YES
GW520 service manual
Cable insert Cable insert
1. Change cable 1. Change cable
2. Check soldering 2. Check soldering
or change FL300 or change FL300
Check soldering Check soldering
or change U301 or change U301
Change U301 Change U301
or main board or main board
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5. Trouble shooting
LGE Internal Use Only