Usb Trouble Shooting - LG D690 Service Manual

3.18 USB Trouble shooting

The sequence of LGD690USB is,
USB connected to LGD690->VBUS_USB_IN(C89107) goes to 5V -> USB_D+ go to 3.3V -> USB_DATA is triggered
-> USB work
Check the Connection of
uUSB and Battery?
Check VBUS_USB_IN voltage
(4.7 ~ 5V, TP1 : C9107)?
Check +4V9_VCHG_LDO voltage
(4.6 ~ 5V, TP2 : C9112)?
Check +3V3_MTK_VUSB
(TP3 : C2336) is high ?
(TP4 : FL9101) is high?
Changed the main board
LGE Internal Use Only
START
Yes
Yes
Yes
Yes
USB_D_P
Yes
No
Change or charging the Battery
No
Change TA or uUSB cable
No
Check 94100(ChargerIC)
No
Check U4100(MT6323)
No
Check FL9101, uUSB cable
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3. TROUBLE SHOOTING
Only for training and service purposes