3. TROUBLE SHOOTING
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3.21 USB Trouble shooting
The sequence of D821 USB is,
USB connected to D821 -> VBUS_USB_IN(FL16003) goes to 5V -> USB_DATA is triggered -> USB work
USB Trouble shooting is shown below.
Battery voltage higher than 3.2V?
START
Pin 30~35 of CN16000 are about 5V?
[VBUS_USB_IN_PM]
Pin 11~12 of CN16000 are open?
[USB_HS1_DP/DM SLIM1]]
Pin 11, 12 of CN16000 are USB Signal?
Charge or Charging the battery.
Insert USB Cable
Change Lower FPCB
If the pin 11~12 of CN16000 are short
Rework(Replace) the D16001
END
Check the Lower FPCB
No
No
No
No
Yes
Yes
Yes
Yes