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4.11 Key Sense Trouble
Key Sense sequence of U880 is :
Default condition ROW(0-4) is 2.7V -> Press the key -> Corresponding row(x) and col(x) go to 0V ->
Key sensing
4. TROUBLE SHOOTING
- 102 -
Start
Work well?
Check the RA600,
R603 with no key press
Change the Main board
End
Yes
NO
Change the side key
pcb
Check the RA600,
R603 with key press
NO
ROW(0-4) is 2.7V?
Check RA600,R603
NO
YES
Side Key
For Camera
RA600
R603
Side Key
For Volume
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 ...