Usb Trouble Shooting - LG -P940 Service Manual

4.11 USB Trouble shooting

The sequence of LGP940USB is,
USB connected to LGP940
USB work
Block Diagram of USB & UART connection is shown below
Start
START
Cable is inserted?
Cable is inserted?
YES
Yes
C816 is 5V?
TP1 is 5V?
YES
Yes
USB_D+ is 3.3V?
TP USB_D+is 3.3V?
YES
Change the Main board
Yes
Change the mainboard
LGE Internal Use Only
USB_VBUS(C719) goes to 5V
NO
Insert cable
No
NO
Check MUIC or
Charger IC
No
Check MUIC or Charger IC
NO
Check IC701
No
- 105 -
USB_D+ go to 3.3V
Insert cable
Check IC701
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4. TROUBLE SHOOTING
USB_DATA is triggered
Only for training and service purposes