I/O Connector - Huawei U8950 Maintenance Manual

U8950 Maintenance Guide V1.0

10.3.7 I/O Connector

Circuit Block Diagram
Working Principle
When connected to the I/O connector (USB connector), a charger provides the VCHG
charging voltage to charge the battery.
When the phone is connected to a computer using a USB cable, USB_HS_DN
and USB_HS_DP are used for communication (for upgrading the phone's firmware, reading
information from the phone and so on) between the phone and the computer.
Troubleshooting Process
Failure: The phone cannot be charged or detected by a computer.
Solution: Clean, re-solder, or replace the USB connector.
Circuit Diagram Symbols in this Section
Signal Name
VCHG
USB_DM
USB_DP
2012-10-22
Function
Charging current input
Digital signal
Digital signal
Huawei Proprietary and Confidential
10 Principles and Failure Analysis
Test Reference Value or Oscillogram
High level, 5 V
None
None
86