LG GW620 - USB Trouble

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4. TROUBLE SHOOTING
4.12. USB trouble
USB Initial sequence of GW620 is :
USB connected to GW620 Æ VCHG_VBUS(FL700) go to 5V
Æ VERG_MSME_1.8V is about 1.8V Æ USB_CLK is OK(R312)->USB work
Start
TP1 is about
to 5V?
TP2(Clock) is OK?
Change the Main board
Check FL1
Check U5
NO
YES
YES
NO
Cable is insert?
YES
Cable insert
NO
YES
NO
Check U33
TP3 is about
to 1.8V?