Usb Trouble Shooting - LG -P768 Service Manual

4.11 USB Trouble shooting

4.10 USB Trouble shooting
The sequence of LGP760USB is,
The sequence of LGP768USB is,
USB connected to LGP760  USB_VBUS(C716)goes to 5V  USB_D+ go to 3.3V  USB_DATA is triggered  USB
USB connected to LGP768 -> USB_VBUS(C716)goes to 5V -> USB_D+ go to 3.3V-> USB_DATA is triggered -> USB work
work
Block Diagram of USB & UART connection is shown below
Block Diagram of USB & UART connection is shown below
Cable is inserted?
C719(TP1)
USB_D+(TP2) is
Change the Main board
LGE Internal Use Only
START
Start
Cable is inserted?
NO
Yes
YES
C719(TP1) is 5V?
NO
is 5V?
Yes
YES
NO
USB_D+ (TP2) is 3.3V?
3.3V?
Yes
YES
Change the mainboard
No
Insert cable
Insert cable
No
Check MUIC or Charger IC
Check MUIC or
Charger IC
No
Check IC701
Check IC701
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4. TROUBLE SHOOTING
Only for training and service purposes