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4.9 USB Trouble
USB Initial sequence of U880 is :
USB connected to U880 -> USB_VBUS(U401 Pin_4) go to 5V -> USB_D+(U401 Pin_1) go to 3.3V ->
48M Crystal on -> USB_DATA(TP_200) is triggered -> USB work.
4. TROUBLE SHOOTING
- 100 -
Start
USB_VBUS is about
to 5V?
USB_D+ is about to 3.3V?
48M is run?
Change the Main board
Check U401,D401,USB
cable
Check U401
Check X200
NO
YES
YES
YES
NO
NO
Cable is insert?
YES
Cable insert
NO
X200(48MHz)
USB_D+
USB_D
-
USB_VBUS
USB_DATA
(TP200)
Summary of Contents for U880
Page 1: ...Date November 2005 Issue 1 0 Service Manual Model U880 Service Manual U880 ...
Page 20: ...3 TECHNICAL BRIEF 21 ...
Page 32: ...3 TECHNICAL BRIEF 33 Figure 3 5 6 1 GSM PA functional block diagram ...
Page 35: ...3 TECHNICAL BRIEF 36 Figure 3 5 10 1 Bluetooth system architecture ...
Page 50: ...3 TECHNICAL BRIEF 51 Figure 3 10 3 2 1 PM6650 Functional Block Diagram ...
Page 114: ...4 TROUBLE SHOOTING 115 Loud Speaker U502 U503 Amp ...
Page 118: ...4 TROUBLE SHOOTING 119 C200 C201 for MIC serial capacitor ...
Page 121: ...4 TROUBLE SHOOTING 122 Q404 Q403 Q402 VBATT GND ...
Page 128: ...5 DOWNLOAD 129 5 Choose a Module Image file after clicking on the Browse button ...
Page 143: ...6 BLOCK DIAGRAM 144 6 3 Interface Diagram U880 Interface Diagram ...
Page 145: ... 146 ...
Page 154: ... 155 8 PCB LAYOUT ...
Page 155: ... 156 8 PCB LAYOUT ...
Page 156: ... 157 8 PCB LAYOUT ...
Page 157: ... 158 8 PCB LAYOUT ...
Page 158: ... 159 8 PCB LAYOUT ...
Page 159: ... 160 8 PCB LAYOUT ...
Page 166: ...9 CALIBRATION 167 Click START button U880 U880_ver1 1 U880 U880 Click U880 ...
Page 167: ... 168 ...
Page 168: ... 169 ...
Page 170: ... 171 ...
Page 171: ... 172 ...
Page 196: ...Note ...
Page 197: ...Note ...